| Word | Description |
| A Record | A Record Short for Address Record. It links a name to an IP address (or sometimes to another name). It is used within DNS, where each entry in the DNS table (an A Record) maps a domain name or sub-domain to an IP Address. |
| A/V | audio/video |
| AC | AC 1. Alternating Current. An electrical current that alternates its direction of flow (cf DC). The frequency (or number of cycles per second) is measured in hertz. 2. Air Conditioning. Air Conditioning units (which cool and de-humidify the air) are often rated in BTUs. 3. Administrator Account. A user account with full administrative rights. Depending on the context and operating system an administrator account may have full administrative rights over the local pc or over all pcs in a domain. cf LUA. |
| Access | Microsoft Access, often abbreviated "MS Access," is a popular database application for Windows. Access allows users to create custom databases that store information in an organized structure. The program also provides a visual interface for creating custom forms, tables, and SQL queries. Data can be entered into an Access database using either visual forms or a basic spreadsheet interface. The information stored within an Access database can be browsed, searched, and accessed from other programs, including Web services. While Access is a proprietary database management system (DBMS), it is compatible with other database programs since it supports Open Database Connectivity (ODBC). This allows data to be sent to and from other database programs, such as MS SQL, FoxPro, Filemaker Pro, and Oracle databases. This compatibility also enables Access to serve as the back end for a database-driven website. In fact, Microsoft FrontPage and Expression Web, as well as ASP.NET have built-in support for Access databases. For this reason, websites hosted on Microsoft Windows servers often use Access databases for generating dynamic content. File Extension: .MDB |
| Access Control | Access Control ensures that resources are only granted to those users who are entitled to them. |
| Access Point | An access point provides wireless access to a network. Devices connected to an access point can communicate with other devices on the network. They may also connect to the Internet if the access point is linked to an Internet connection, which is commonly the case. Access points that use Wi-Fi are also called base stations. Example: "The coffee shop provides an access point for customers with Wi-Fi devices." |
| Access Speed | The average amount of time it takes for a floppy drive, hard drive, CD drive, or other drive to find any particular piece of data on a disk and send it to your PC. Access speed is typically listed in milliseconds (ms). |
| Account Harvesting | Account Harvesting is the process of collecting all the legitimate account names on a system. |
| ACE | Access Control Entry. A single entry in an access control list. |
| ACK | Short for Acknowledgement. Typically refers to an Acknowledgement message. |
| ACK Piggybacking | ACK piggybacking is the practice of sending an ACK inside another packet going to the same destination. |
| ACPI | Advanced Configuration and Power Interface. |
| ACPI (Advanced Configuration and Power Interface) | This power management interface takes the power management out of the BIOS and gives control to the operating system (OS). Typically, a system’s BIOS is only able to turn a device off after a certain period of inactivity. With ACPI, the user can instruct the OS to slow down the processor or enter sleep mode. This basically gives the OS, and thus the user, more control of power management. |
| Active Collection / Seed | collections or seed URLs that are scheduled for crawling. |
| active content | Refers to content on a Web site that is either interactive, such as Internet polls or opt-in features, or dynamic, such as animated GIFs, stock tickers, weather maps, JavaScript applications, embedded objects, streaming video and audio or ActiveX applications. Streaming video and audio rely on browser plug-ins, such as RealPlayer, to display active content. |
| Active Directory | A Microsoft technology based on LDAP that provides a unified view and way to manage all objects on a network. Microsoft created Active Directory as a response to Novell’s NDS system that allows administrators to control large networks in a similar manner. Active Directory was first introduced with Windows 2000, and many organizations are moving from the domain model of Windows NT to the Active Directory model of Windows 2000 because |
| Active Matrix | LCD panels that are active matrix have a sharper, brighter image than those with passive matrix screens. They can also continue to be seen at much greater angles off of central viewing. In the early days of the LCD active matrix panels cost more to produce. The “active” part of the word describes the use of a transistor or diode that actively controls each pixel. |
| ActiveX | This Microsoft-based technology was built to link desktop applications to the World Wide Web. Using ActiveX development tools, software developers can create interactive Web content for their applications. For example, Word and Excel documents can be viewed directly in Web browsers that supports ActiveX. While ActiveX is a useful technology, the downside is that you need to have a up-to-date version ActiveX installed on your machine in order to use ActiveX-enabled content. |
| Activity Monitor | Activity Monitor is a utility for performing different tasks to a computer process in the Mac OS X operating system. Some of its functions include: Quitting or "killing" a computer process Viewing the computer's CPU load Checking the amount of random access memory in use or swapped out Checking the amount of hard disk read-ins and write-outs Checking the capacity of storage devices Monitoring the computer's network usage Inspecting running computer processes Viewing a process identifier number Viewing information about a particular process |
| Activity Monitors | Activity monitors aim to prevent virus infection by monitoring for malicious activity on a system, and blocking that activity when possible. |
| Actuator | The part of a hard drive that the read/write arms attach to. It is controlled by an electrical signal sent to it that extends or retracts the arms so that they can move across the tracks on the drive platters. Nowadays the movement of these lightweight arms is very fast, appearing like a flicker if you were to view it. |
| AD | 1. Active Directory. 2. Administrative Domain. Refers to groups of computers and the network infrastructure operated and managed by a single organisation. 3. Abbreviation for the Latin phrase "Anno Domini", which means "in the year of our Lord". It denotes that a year is after the believed year of birth of Christ. "Anno Domini" is actually an abbreviation of "Anno Domini Nostri Jesu Christi" which means "in the year of our Lord Jesus Christ." 4. Abbreviation for "Advertisement". This can refer to any form of advertisement, including banner ads, pop-up (or pop-behind) advertisements, tv or radio advertisements etc. 5. Analogue to Digital conversion or Analogue to Digital converter. The process of converting an analogue input to a digital output. |
| Ad Hoc Network | "Ad Hoc" is actually a Latin phrase that means "for this purpose." It is often used to describe solutions that are developed on-the-fly for a specific purpose. In computer networking, an ad hoc network refers to a network connection established for a single session and does not require a router or a wireless base station. For example, if you need to transfer a file to your friend's laptop, you might create an ad hoc network between your computer and his laptop to transfer the file. This may be done using an Ethernet crossover cable, or the computers' wireless cards to communicate with each other. If you need to share files with more than one computer, you could set up a mutli-hop ad hoc network, which can transfer data over multiple nodes. Basically, an ad hoc network is a temporary network connection created for a specific purpose (such as transferring data from one computer to another). If the network is set up for a longer period of time, it is just a plain old local area network (LAN). |
| ADC (Analog-to-Digital Converter) | Stands for "Analog-to-Digital Converter." Since computers only process digital information, they require digital input. Therefore, if an analog input is sent to a computer, an analog-to-digital converter (ADC) is required. This device can take an analog signal, such as an electrical current, and digitize it into a binary format that the computer can understand. A common use for an ADC is to convert analog video to a digital format. For example, video recorded on 8mm film or a VHS tape is stored in an analog format. In order to transfer the video to a computer, the video must be converted to a digital format. This can be done using an ADC video conversion box, which typically has composite video inputs and a Firewire output. Some digital camcorders that have analog inputs can also be used to convert video from analog to digital. ADCs may also be used to convert analog audio streams. For example, if you want to record sounds from a microphone, the audio must be converted from the microphone's analog signal into a digital signal that the computer can understand. This is why all sound cards that have an analog audio input also require an ADC that converts the incoming audio signal to a digital format. The accuracy of the audio conversion depends on the sampling rate used in the conversion process. Higher sampling rates provide a better estimation of the analog signal, and therefore produce a higher-quality sound. While ADCs convert analog inputs into a digital format that computers can recognize, sometimes a computer must output an analog signal. For this type of conversion, a digital-to-analog converter (DAC) is used. NOTE: ADC can also stand for "Apple Display Connector," which was a proprietary video connector developed by Apple. It combined DVI, USB, and AC power into a single cable. Apple stopped producing computers with ADC ports in 2004 in favor of the standard DVI connection. |
| Address Munging | Address Munging is the process of modifying an e-mail address to make it invalid, in such a way that a legitimate reader can put it back together again. This technique is used to hide (valid) e-mail addresses from e-mail harvesters (and thus reduce the likelihood of receiving spam). |
| ADO | ADO: Microsoft® ActiveX® Data Objects. Encompasses the functionality of both RDO and DAO. |
| ADS | 1. Active Directory Service. 2. Active Directory Structure. 3. Automated Deployment Services. |
| ADSL | (Asymmetric Digital Subscriber Line) A DSL line where the upload speed is different from the download speed. Usually the download speed is much greater. |
| Advanced Host Controller Interface (AHCI) | The Advanced Host Controller Interface (AHCI) is an application programming interface defined by Intel which defines the operation of Serial ATA host bus adapters in a non-implementation-specific manner. The specification describes a system memory structure for computer hardware vendors to exchange data between host system memory and attached storage devices. As of June 2008, the current version of the specification is v. 1.3.[1] AHCI gives software developers and hardware designers a standard method for detecting, configuring, and programming SATA/AHCI adapters. AHCI is separate from the SATA 3Gb/s standard, although it exposes SATA's advanced capabilities (such as hot-plugging and native command queuing) such that host systems can utilize them. Many SATA controllers offer selectable modes of operation: legacy Parallel ATA emulation, standard AHCI mode, or vendor-specific RAID. Intel recommends choosing RAID mode on their motherboards (which also enables AHCI) rather than the plain AHCI/SATA mode for maximum flexibility, due to the issues caused when the mode is switched once an operating system has already been installed.[2] Legacy mode is a software backward-compatibility mechanism intended to allow the SATA controller to run in legacy operating systems which are not SATA-aware or where a driver does not exist to make the operating systems SATA-aware. AHCI is fully supported out of the box for Windows Vista and Linux operating systems from kernel 2.6.19, as well as later operating systems such as Windows 7. NetBSD also supports drivers in AHCI mode out of the box in certain versions. OpenBSD has had an AHCI driver starting with OpenBSD 4.1. DragonFlyBSD based its AHCI implementation on OpenBSD's and added extended features such as port multiplier support. FreeBSD supports AHCI as well. Solaris 10 introduced AHCI support in the 8/07 release [3]. Older operating systems require hardware-specific drivers to support AHCI. |
| Advanced Micro Devices (AMD) | Advanced Micro Devices, Inc. (AMD) (NYSE: AMD) is an American multinational semiconductor company based in Sunnyvale, California, that develops computer processors and related technologies for commercial and consumer markets. Its main products include microprocessors, motherboard chipsets, embedded processors and graphics processors for servers, workstations and personal computers, and processor technologies for handheld devices, digital television, automobiles, game consoles, and other embedded systems applications. |
| Advanced SCSI Programming Interface (ASPI) | This was developed by Adaptec so that different devices could be controlled by different SCSI cards, and therefore the SCSI card version would not matter. Basically, if the correct ASPI driver is being used, you can send the same command to any Adaptec SCSI card to make something happen to a device. Most commonly, ASPI is associated with CD-ROM and CD-RW drives. |
| Adware | Adware A collective name for software which displays advertising banners or pop-ups while the user is using the application. Typically the software may be free at the point of use and is supported by the revenue generated from displaying advertisements. Sometimes the advertisements are independent of the application the user originally installed. Adware can be distracting and sometimes annoying, but other than taking up bandwidth (because the application will typically download new adverts) it is not in itself harmful. |
| AES | Advanced Encryption Standard. An encryption standard widely seen as more secure and a natural successor to 3DES and DES. |
| AFAIK | Online speak for “As Far As I Know” |
| Affiliate | Website affiliates are what drive Internet marketing. Companies run affiliate programs to generate leads and sales from other Websites. They pay the sites who host their ads a commission for products sold through the links on their sites. For example, if a site owner signs up for Amazon.com's affiliate program, he will receive ad banners or links from Amazon.com that he can place anywhere on his site. Then, if a visitor clicks on the Amazon.com banner or a link on his site and buys something, he will receive a commission. Unfortunately for Website owners, affiliate commisions are seldom above 5%, since most Web sales are made with small profit margins. The introduction of Website affiliate programs in the late 1990s brought Internet marketing to a new level. The first companies that offered these programs saw sales increase dramatically. After all, these companies basically get free advertising and only pay their affiliates a percentage of the sales they generate. It is a win-win situation for the company that runs the affiliate program. The only drawback is that the programs take a lot of work (and sometimes a lot of money) to set up and maintain. Thus, smaller companies may not find it very beneficial to offer an affiliate program. |
| AFK | Online speak for “Away From Keyboard” |
| AGP | Advanced Graphics Port. Graphics card interface for high performance graphics (faster than PCI). Specification Denoted Notes AGP 1.0 AGP AGP x1 AGP x2 Supports 1x and 2x adapter cards. Uses a signal level of 3.3 volts. AGP 1.0 adapter cards have a different slot arrangement from AGP 2.0 (and later) and therefore an AGP 1.0 adapter card will not fit into an AGP 2.0 slot. AGP 2.0 AGP x4 Supports 4x adapter cards, i.e. 4 times faster than the original AGP specification. Uses a signal level of 1.5 volts. AGP 3.0 AGP x8 Supports 8x adapter cards. Uses a signal level of 0.8 volts. The slot for AGP 3.0 is identical to that for AGP 2.0. AGP 2.0 and AGP 3.0 cards and motherboards should be compatible with each other - but an AGP 8x card fitted to a motherboard that only supports AGP 4x will be forced to work at the slower 4x rate. |
| AGP (Accelerated Graphics Port) | A dedicated expansion port that began to show up on motherboards in the second half of 1997. It bypasses the PCI bus and allows higher throughput from the graphics card to the processor and memory for speedier 3D graphics. Original AGP cards were “1x” versions that ran at 66MHz, offering 266MB/second throughput; but now AGP supports up to 8X data transfer speeds, which means the card still runs at 66MHz, but transfers 8x as much data per clock tick, upping the throughput to 2.1GB/second. Although the throughput is much greater, most graphics cards have a large amount of local memory and thus do not get much of a bonus from faster AGP speeds. |
| AGP 1x | The original parallel AGP standard that operates on a 32-bit bus at 66MHz speed for a maximum data transfer rate of 256MB/second. |
| AGP 2x | This AGP standard features a parallel 32-bit bus running at 133MHz effectively (66MHz*2 literally) for a maximum data transfer rate of 512MB/second. AGP 2x slots will accept AGP 1x cards as well as 2x cards. |
| AGP 4x | This AGP standard features a parallel 32-bit bus running at 266MHz effectively (66MHz*4 literally) for a maximum data transfer rate of 1GB/second. AGP 4x slots are compatible with 1x, 2x, and 4x graphics cards. |
| AGP 8x | This AGP standard features a parallel 32-bit bus running at 533MHz effectively (66MHz*8 literally) for a maximum data transfer rate of 2GB/second. This is the last parallel form of AGP, and is compatible with all previous AGP cards. |
| AGP Aperture | The amount of system memory that the AGP board can address and use as graphics memory. Often, the default setting is 64 MB. Increasing this value (assuming you have enough system memory) may increase performance in 3D games that use more memory than is available on the video card. Once an AGP video card is installed, this setting can usually be changed in the computer’s BIOS. |
| AGP Pro | This AGP standard allows the graphics card to draw more than four times the electrical power of the regular AGP 4x standard, i.e., 110 watts up from 25 watts. AGP Pro transfers data at the same speed as AGP 4x and requires a special AGP Pro slot that is larger than the standard AGP slot. |
| AHCI | Advanced Host Controller Interface (specification). |
| AI | Artificial Intelligence. The emulation of intelligent behaviour by software (and or machines). |
| AIFF | Stands for "Audio Interchange File Format." AIFF is an audio format originally developed by Apple Computer for storing high-quality sampled audio data. AIFF files are similar to Windows WAVE files in both size and quality. Both AIFF and WAVE files can hold CD quality audio and therefore can be burned onto an audio CD. Though the AIFF format was created by Apple, audio programs on both the Mac and PC can typically read the files. File extensions: .AIF, .AIFF |
| Air Cooling | Cooling that involves a heatsink and/or fan. Even though a metal heatsink may make contact with the microprocessor package (or whatever is being cooled), the heatsink ultimately exchanges the heat with air, whether a fan is used or not. Contrast this with water cooling. Air cooling is less efficient than water cooling. |
| Air gap | A type of network security in which a network is secured, at least in part, by keeping it physically separate from other local networks and the Internet. This can be an effective type of security, but it is also limiting in that clients may not be able to get to all resources they need from a single computer. |
| AJAX | AJAX Asynchronous JavaScript and XML. A development technique for web pages that uses JavaScript and XML to create dynamic web page content, which has the capability to be updated as the user interacts with it. AJAX is described as asynchronous because it allows data to be exchanged with the server and parts of the page updated dynamically without delay to the user experience or the need to reload the entire page. The philosophy behind AJAX is to load the static parts of a webpage once, updating the dynamic parts (i.e. those bits which can change) as necessary without needing to reload anything unnecessary (such as the static parts of the page). This makes small updates much faster, because the majority of the page is unchanged and does not need to be reloaded. As well as a quicker user experience, AJAX also reduces the amount of data that needs to be downloaded from the server to the client, reducing bandwidth and potentially also processing requirements. AJAX makes use of and builds upon JavaScript, XML, HTML and CSS. There is some dispute over whether or not the name should be capitalised, i.e. AJAX or Ajax. The argument in favor of not capitalizing the name is that Ajax stands for an approach rather than an acronym. |
| Aka | Also Known As. Used to refer to other names for something. Aka may be used to indicate more or less common names. For example "sol aka the sun". Aka is also expressed as A.K.A. i.e. with a period between each letter. It is pronounced A-K-A, emphasising each letter in turn. |
| Alert Box | An alert box, sometimes called a message box, is a small window that pops up on your screen to warn you that your computer is about to perform an operation with potentially damaging consequences. For example, when you choose to empty the Trash or Recycle Bin on your computer, an alert box may pop up, saying "Are you sure you want to permanently remove these items?" You are then given the choice to select "OK," to delete the items, or "Cancel," to prevent the items from being removed. Alert boxes act as a safeguard for users, preventing us from doing things we wish we hadn't. Perhaps the most common alert box is the one that pops up when you try to close a document without saving it. You'll mostly likely see an alert box with the message, "Save changes to this document before closing?" You can select "Don't Save," to discard the changes, "Save," to save the changes before closing the document, or "Cancel," to cancel closing the document and continue working on it. Most alert boxes include the standard alert icon -- a triangle with an exclamation point in the middle -- to get your attention. However, not all alert boxes have multiple options, such as "Cancel" and "OK." For example, an alert box may show up on your screen saying a program performed an illegal operation and has unexpectedly quit. When that happens, your only option is to select "OK" and then kick your computer for quitting the program before you had a chance to save your work. |
| Algorithm | Algorithm An organised method for solving a problem (and producing a result). Algorithms are expressed as a finite sequence of clearly defined steps for accomplishing a task or solving a problem. cf heuristic. |
| Alpha Test (Alpha) | A term given to a very early version of a hardware or software product which is not yet stable and may lack features. After some testing and some revision, the product will assume beta status. |
| ALS | Active Line State. A signal or LED indicating that a communication line, connection or cable is in use. |
| Alt (Alternate) | 1. There is an Alt key found on a computer keyboard. The Alt key functions much like a third Ctrl/Shift key in that it alters the value of other characters pressed on the keyboard. 2. The term Alt has also been used to refer to using the Esc key (ASCII 27) to alter the next input. 3. Finally, Alt is used as a prefix for usenet newsgroups that can be created without going through the standard voting procedures, such as alt.pictures.angry.pandas. |
| AMT | Active Management Technology. A specification from Intel for a set of hardware components designed to provide remote management of PCs |
| Analog | As humans, we perceive the world in analog. Everything we see and hear is a continuous transmission of information to our senses. This continuous stream is what defines analog data. Digital information, on the other hand, estimates analog data using only ones and zeros. For example, a turntable (or record player) is an analog device, while a CD player is digital. This is because a turntable reads bumps and grooves from a record as a continuous signal, while a CD player only reads a series of ones and zeros. Likewise, a VCR is an analog device, while a DVD player is digital. A VCR reads audio and video from a tape as a continuous stream of information, while a DVD player just reads ones and zeros from a disc. Since digital devices read only ones and zeros, they can only approximate an audio or video signal. This means analog data is actually more accurate than digital data. However, digital data can can be manipulated easier and preserved better than analog data. More importantly, computers can only handle digital data, which is why most information today is stored digitally. But if you want to transfer video from old analog video tapes into your computer so you can edit them, you're not out of luck. You can use a digital to analog converter (DAC) to convert the analog information into a digital signal that can be recognized by your computer. |
| Analog Control | An analog control changes value in non-discrete steps. You can tune an analog control to non-distinct values (selecting 107.41234723947392… as the radio station you are tuned to instead of 107.40000000000000…). In some cases, like for volume, analog controls are better. Have you ever used a digital volume control on a new TV, and one setting is too loud while the other is too soft? You just can’t get it in between. However, for channel tuning, where values change by fixed steps, a digital control is much better–you just don’t need to get in between channel 4 and 5. Also see Digital Control |
| Analogue Modem | analogue modem A modem for use with analogue equipment, such as a phone line. Typical analogue modem speeds are: Common name Maximum download speed Maximum upload speed kbps bytes/sec kbps bytes/sec 4.8 4.8 600 4.8 600 9.6 9.6 1200 9.6 1200 14.4 14.4 1800 14.4 1800 28.8 28.8 3600 28.8 3600 33.6k 33.6 4200 33.6 4200 56k v90 53 6600 33.6 4200 Modems can operate at speeds much slower than their rated maximum. Where a cable modem has LEDs on the front, these are typically one or more of: LED Short for Description PWR Power Power-on/ready indicator. MR Modem Ready AA Auto Answer Modem is ready to answer incoming calls. CD Carrier Detect Indicates that the modem has detected a valid carrier signal from the remote modem. (When modems communicate they establish a carrier signal for handshaking purposes.) HS High Speed Indicates if the connection is considered by the modem to be "High Speed" this is at the modem's top speed or above 4800bps (depending on the modem). RD Receive Data Flashes when the modem is receiving data (from the modem at the other end of the link.) SD Send Data Flashes when the modem is sending data (to the modem at the other end of the link). TR Terminal Ready On indicates that the computer (that the modem is locally connected to) is ready to receive data. DTR CS Clear to Send On indicates that the modem is ready to receive data from the computer it is connected to. CTS ARQ/FAX Error correction fax OH Off Hook Indicates that the phone line is active and the modem has control of the line. |
| Anonymous FTP | FTP services requiring no specific authentication, using a login name of “anonymous” and your e- mail address as a password. |
| ANSI | American National Standards Institute. A long standing not-for-profit American standards organisation. |
| Antivirus | Antivirus (or anti-virus) software is used to prevent, detect, and remove malware, including computer viruses, worms, and trojan horses. Such programs may also prevent and remove adware, spyware, and other forms of malware. A variety of strategies are typically employed. Signature-based detection involves searching for known malicious patterns in executable code. However, it is possible for a user to be infected with new malware in which no signature exists yet. To counter such so-called zero-day threats, heuristics can be used. One type of heuristic approach, generic signatures, can identify new viruses or variants of existing viruses by looking for known malicious code (or slight variations of such code) in files. Some antivirus software can also predict what a file will do if opened/run by emulating it in a sandbox and analyzing what it does to see if it performs any malicious actions. If it does, this could mean the file is malicious. However, no matter how useful antivirus software is, it can sometimes have drawbacks. Antivirus software can degrade computer performance if it is not designed efficiently. Inexperienced users may have trouble understanding the prompts and decisions that antivirus software presents them with. An incorrect decision may lead to a security breach. If the antivirus software employs heuristic detection (of any kind), success depends on achieving the right balance between false positives and false negatives. False positives can be as destructive as false negatives. In one case, a faulty virus signature issued by Symantec mistakenly removed essential operating system files, leaving thousands of PCs unable to boot.[1] Finally, antivirus software generally runs at the highly trusted kernel level of the operating system, creating a potential avenue of attack.[2] In addition to the drawbacks mentioned above, the effectiveness of antivirus software has also been researched and debated. One study found that the detection success of major antivirus software dropped over a one-year period. Identification methods ClamWin 0.95.1 running on Windows XP There are several methods which antivirus software can use to identify malware. Signature based detection is the most common method. To identify viruses and other malware, antivirus software compares the contents of a file to a dictionary of virus signatures. Because viruses can embed themselves in existing files, the entire file is searched, not just as a whole, but also in pieces.[9] Heuristic-based detection, like malicious activity detection, can be used to identify unknown viruses. File emulation is another heuristic approach. File emulation involves executing a program in a virtual environment and logging what actions the program performs. Depending on the actions logged, the antivirus software can determine if the program is malicious or not and then carry out the appropriate disinfection actions.[10] [edit]Signature based detection A command-line virus scanner, Clam AV 0.95.2, running a virus signature definition update, scanning a file and identifying a Trojan Traditionally, antivirus software heavily relied upon signatures to identify malware. This can be very effective, but cannot defend against malware unless samples have already been obtained and signatures created. Because of this, signature-based approaches are not effective against new, unknown viruses. Because new viruses are being created each day, the signature-based detection approach requires frequent updates of the virus signature dictionary. To assist the antivirus software companies, the software may allow the user to upload new viruses or variants to the company, allowing the virus to be analyzed and the signature added to the dictionary.[9] Although the signature-based approach can effectively contain virus outbreaks, virus authors have tried to stay a step ahead of such software by writing "oligomorphic", "polymorphic" and, more recently, "metamorphic" viruses, which encrypt parts of themselves or otherwise modify themselves as a method of disguise, so as to not match virus signatures in the dictionary.[11] [edit]Heuristics Some more sophisticated antivirus software uses heuristic analysis to identify new malware or variants of known malware. Many viruses start as a single infection and through either mutation or refinements by other attackers, can grow into dozens of slightly different strains, called variants. Generic detection refers to the detection and removal of multiple threats using a single virus definition. [12] For example, the Vundo trojan has several family members, depending on the antivirus vendor's classification. Symantec classifies members of the Vundo family into two distinct members, Trojan.Vundo and Trojan.Vundo.B.[13][14] While it may be advantageous to identify a specific virus, it can be quicker to detect a virus family through a generic signature or through an inexact match to an existing signature. Virus researchers find common areas that all viruses in a family share uniquely and can thus create a single generic signature. These signatures often contain non-contiguous code, using wildcard characters where differences lie. These wildcards allow the scanner to detect viruses even if they are padded with extra, meaningless code. [15] Padded code is used to confuse the scanner so it can't recognize the threat. A detection that uses this method is said to be "heuristic detection." |
| Anycast | A method available in IPv6 of sending information over a network. It allows a device to send data to the nearest (fastest) of a group of receivers. |
| Apache | The most common web server (or HTTP server) software on the Internet. Apache is an open-source application originally created from a series of changes ("patches") made to a web server written at the National Center for Supercomputing Applications, the same place the Mosaic web browser was created. In early 1995, a group of webmasters decided to get together and expand on the original NCSA HTTP daemon (webserver software), and Apache was born. Today, Apache is the most used webserver on the Internet. Apache is Open Source freeware, and is available for Linux, Windows, and many versions of UNIX. Apache is designed as a set of modules, enabling administrators to choose which features they wish to use and making it easy to add features to meet specific needs inlcuding handling protocols other than the web-standard HTTP. |
| API | 1. Application Programming Interface. The definition of procedures (and protocols) that a software application can make use of. 2. Advance Passenger Information (system). A system for an airlines to send passenger information to a destination airport for customs and immigration purposes before the flight leaves. |
| Apple | The reason this term is in the glossary is because way too many people confuse "Apple" with "Macintosh." Apple is the company that makes Macintosh computers -- not the other way around. Apple's product line includes Power Macs, PowerBooks, iMacs, iBooks, and the popular hard drive-based MP3 player, the iPod. Apple also develops a large number of software programs, such as iTunes, iPhoto, iMovie, and iDVD. Notice a pattern here? Though most of Apple's product names now start with the letter "i", the company has a history of creative innovation. Though Apple has less than ten percent of the marketshare in the computer business, the company still manages to lead the industry in new directions. |
| Applet | A small Java program that can be embedded in an HTML page. Applets differ from full-fledged Java applications in that they are not allowed to access certain resources on the local computer, such as files and serial devices (modems, printers, etc.), and are prohibited from communicating with most other computers across a network. The common rule is that an applet can only make an Internet connection to the computer from which the applet was sent. |
| AppleTalk | Macintosh computers networking protocol. |
| Application | An application, or application program, is a software program that runs on your computer. Web browsers, e-mail programs, word processors, games, and utilities are all applications. The word "application" is used because each program has a specific application for the user. For example, a word processor can help a student create a research paper, while a video game can prevent the student from getting the paper done. In contrast, system software consists of programs that run in the background, enabling applications to run. These programs include assemblers, compilers, file management tools, and the operating system itself. Applications are said to run on top of the system software, since the system software is made of of "low-level" programs. While system software is automatically installed with the operating system, you can choose which applications you want to install and run on your computer. Macintosh programs are typically called applications, while Windows programs are often referred to as executable files. This is why Mac programs use the .APP file extension, while Windows programs use the .EXE extension. Though they have different file extensions, Macintosh and Windows programs serve the same purpose and can both be called applications. |
| Application Failover | The capability of an application to recover from the failure of a database (that the application is connected to and using) by automatically switching over to using a surviving database instance. Application Failover should provide no loss of data or continuity. It tends to be used with high end database systems, such as Oracle Parallel Server (OPS). Also known as ‘run-time failover’. Application Failover is often used in connection with Connection Failover. |
| Application Programming Interface (API) | APIs allow you to program to a pre-constructed interface (the API) instead of programming a device or piece of software directly. This allows for faster development, since programming to a device’s API is designed to be easier than programming to a device directly. APIs allow you to program without having intimate knowledge of the device or software to which you are sending commands. For example, the OpenGL API allows you to create 3D effects without actually knowing the innards of your video card. |
| Application Server | Server software that manages one or more other pieces of software in a way that makes the managed software available over a network, usually to a Web server. By having a piece of software manage other software packages it is possible to use resources like memory and database access more efficiently than if each of the managed packages responded directly to requests. |
| Apt-get | Part of “apt,” a package retrieval tool that automatically connects to known Linux package repositories and checks for new packages. It also works out dependencies between packages. Apt-get is used with the Debian Linux distribution. |
| Archive | As a noun, this refers generally to any type of backed-up data. It can refer to tapes, disks, or just simply a group of data that is an old copy of current data. That copy could be one minute old or several years old. As a verb, archive is the act of backing up data or creating an archive. |
| ARP | Address Resolution Protocol. A network protocol used for mapping an IP address to a physical hardware address (MAC Address). |
| Array | 1. This can be an abbreviation for a group of hard drives functioning as a RAID (Redundant Array of Inexpensive Drives). 2. This also describes a common data structure that holds values in a consecutively numbered group, such as A[1]…[7], where A is an array of 7 different values. There are also multi-dimensional arrays such as A[1,1,1]…A[8,8,8], which can hold many values and still be fairly simply referenced. |
| ASCII | American Standard Code for Information Interchange. In ASCII the letters of the alphabet, digits and various punctuation symbols are assigned a unique 7 bit number (0-127). cf Unicode. On most systems there is also an additional set of 128 "extended ASCII codes" that are used to represent a variety of other symbols. These extended codes are not part of the ASCII standard. |
| ASCII file | A file that can be opened and read by standard text editor programs (for example, Notepad or Simple Text) on almost any type of computer. Also referred to as "plain text files". Examples: documents saved in ASCII format within word processors like Microsoft Word or WordPerfect; e-mail messages created by a program like Outlook; or HTML files. |
| ASDL | 1. Asynchronous Digital Subscriber Line. Provides a permanent link to the internet. 2. Asymmetric Digital Subscriber Line. Technology allowing high data rates over existing copper telephone lines. ASDL supports from 1.5mbps to 9mbps download and from 15kbps to 640kbps upload. |
| ASFN | Alliance for Spam Free Networks. An alliance developed with the mission of creating a spam free internet, targeted membership includes ISPs and large companies. |
| ASIO | Audio Stream Input/Output. |
| ASP | 1. Active Server Pages. A specification for a dynamically created web page. Allows a script or ASP application to be executed on a web server to generate a web page sent to a viewer. Requires IIS. cf JSP. Pages generated using ASP generally have the file extension of .asp. |
| ASP.NET | ASP.NET Microsoft's server based framework for running .NET code on web servers. Similar model to ASP, but for running ASP.NET applications. Requires a web server running IIS. ASP.NET applications can be written using a text editor, but are normally developed using an IDE such as Microsoft's Visual Studio .Net or Borland's Delphi. |
| Aspect Ratio | The ratio of the width by the height on a monitor or television screen. Most TVs and monitors have a 4×3 aspect ratio–the screens are 4 units wide and 3 units high. A movie screen has an aspect ratio of 16×9 (a bit wider than 5×3), and that’s why we have letterboxed movies (when you show a movie in true form on a TV you get black boxes on the top and bottom of the screen). HDTV screens today and some monitors support 16×9 aspect ratios, but most televisions and monitors still retain the 4×3 aspect ratio. |
| ASPI (Advanced SCSI Programming Interface) | This was developed by Adaptec so that different devices could be controlled by different SCSI cards, and therefore the SCSI card version would not matter. Basically, if the correct ASPI driver is being used, you can send the same command to any Adaptec SCSI card to make something happen to a device. Most commonly, ASPI is associated with CD-ROM and CD-RW drives. |
| ASR | 1. Automatic Speech Recognition. Any system for translating speech into commands or for translating speech into an electronic document. 2. Access Service Request. |
| Assembly Language | A programming language specific to a microprocessor. It is a very low-level language, where you actually give the processor instructions like “MOV A,B”, which moves a value from one register to another. As you might imagine, programming directly in assembly language is quite tedious. Thus, higher level languages, such as C++, Visual Basic, or Java, are normally used and then compiled into assembly language specific to the microprocessor on which the program will be run. The compiler tries to optimize the code during this process (e.g., “MOV A,B” followed by “MOV B,C” might be replaced by “MOV A,C”). Depending on how elegant the optimization is, the code may run faster than if no optimization is used. Today, very small and fast programs can be created by using assembly language (defeating code bloat), but assembly language programming is becoming a dying art. |
| ASTA | Anti-Spam Technical Alliance. ASTA was formed in April 2003 to recommend actions and policies for ISPs and e-mail service providers, governments, private corporations and online marketing organisations. It consists of several large companies, including Yahoo, Microsoft, AOL and Earthlink Inc. |
| Asynchronous | This word is used in the telecommunications and distance learning fields. It has a similar meaning in both fields. In telecommunications, it refers to an exchange of data at intermittent, or non-synchronized intervals between two devices. In the distance learning field, it refers to learning systems in which the instructor and students do not have to synchronize their presence. The use of Web-based discussion boards is an asynchronous distance learning activity, because the students and instructor can post their thoughts to the board at any time. The SVETN electronic classrooms and the Holton Governor's School LearnLinc system are synchronous distance leaning activities, because they require the facilitator and students to synchronize their presence. |
| AT Form Factor | A PC form factor that describes the way a motherboard fits into a case and works with a power supply. Thus, you match an AT power supply with an AT case and an AT motherboard. Some of the things common to AT motherboards are a large 5-pin DIN socket for plugging a keyboard in, and serial and parallel port interfaces available via riser cards that are not part of the motherboard itself. The AT form factor was succeeded by the ATX form factor. |
| ATA | AT Attachment. A popular 16-bit interface standard that extends the ISA bus of the IBM PC-AT to attach peripherals;. It has been developed through a number of generations. The original ATA specification defined what was commonly known as Integrated Drive Electronics (IDE). Later versions defined EIDE and then higher speed interfaces. ATA Version Also known as Bus width Maximum dData rate Notes ATA-1 IDE 8 or 16 bit 8.3MB/sec 40 pin ribbon cable. Maximum of two devices. ATA-2 EIDE Fast ATA Fast IDE 8 or 16 bit 16.6MB/sec Maximum number of devices increased to four. ATA-3 16 bit 16MB/sec CRC added. ATA-4 Ulta-ATA/33 16 bit 33MB/sec ATA-5 Ulta-ATA/66 16 bit 66MB/sec 80 pin ribbon cable, 40 pin connector (extra cables for noise reduction). These cables typically have three connectors. The blue connector should be plugged into the mother board, the grey (middle) connector to any slave device and the grey (end) connector to the master device. ATA-6 Ultra-ATA/100 16 bit 100MB/sec ATA-7 Ultra-ATA/133 16 bit 130MB/sec ATA is but is now generally referred to as PATA to distinguish it from SATA. SATA uses a totally different interface from PATA and is seen as its natural successor. |
| ATA (AT Attachment) | A storage (hard drive, CD-ROM, etc.) interface more commonly known as IDE. The “AT” refers to the IBM-AT computer where this interface was first used. |
| ATA/100 (Ultra ATA/100) | Another extension to the ATA interface that adds a 50% increase in top speed over ATA/66, getting to 100MB/second, up from 66MB/second. This standard also adds some additional error-checking not found in earlier ATA standards. Like Ultra ATA/66, ATA/100 requires an 80-conductor cable to work at full speed. |
| ATA/133 (Ultra ATA/133) | This refers to what is most probably the final extension to the parallel ATA connection standard. The proposal was created by Maxtor, and allows a top data transfer rate of 133 megabytes per second. Intel didn’t support this standard in its chipsets, instead opting to wait for Serial ATA. See Serial ATA for further details. |
| ATA/33 (Ultra ATA/33) | An extension to the ATA interface (IDE) that effectively doubles the top data transfer speed of IDE from 16.6MBytes/second up to 33 MBytes/second. Also known as Ultra-IDE. |
| ATA/66 (Ultra ATA/66) | An extension to the ATA interface (IDE) proposed by Quantum that effectively doubles the data transfer speed of the Ultra ATA/33 interface to 66MBps. To achieve the increase in speed you must use a special 80-conductor cable with 40 data lines and 40 ground lines to keep the signal stable. |
| ATM (Asynchronous Transfer Mode) | A networking protocol initially designed to move multimedia data around with high reliability and speed. It uses small, fixed-size cells of data that can be more easily controlled and kept at specific service levels than TCP/IP. Some ISPs use ATM as the protocol for their backbones. |
| Attachment | A file embedded in an e-mail message. It is possible to have one or more attachments embedded in an e-mail message. If you are sending or receiving attachments, you must have an e-mail client that supports MIME encoding, or the attachments will show up in encoded form, which basically looks like a large block of numbers and letters. |
| ATX Form Factor | The ATX form factor specification takes the original Baby AT-sized motherboard, rotates it 90 degrees, and calls for a power supply with a side-mounted fan that cools not only the power supply, but also the processor and add-in boards. This new approach was designed to lower costs and provide better motherboard placement in an ATX case. In addition, the ATX form factor introduced a large set of I/O ports that are wired directly to the motherboard, and standard support for PS/2 keyboard and mouse connections. |
| ATX12V | A superset of the ATX form factor that is used for systems with the Pentium 4 processor. It features a power supply with an extra four-pin connector for 12 volt power to the motherboard so that the processor has enough power. There is also a 6-pin auxiliary connector for additional 3.3 or 5 volt power. |
| Auditing | Auditing is the information gathering and analysis of assets to ensure such things as policy compliance and security from vulnerabilities. |
| AUI | A synonym for the 10Base5 Thicknet Ethernet standard. |
| Authorization | Authorization is the approval, permission, or empowerment for someone or something to do something. |
| Autonomic Computing | Autonomic Computing is an initiative started by IBM in 2001. Its ultimate aim is to develop computer systems capable of self-management, to overcome the rapidly growing complexity of computing systems management, and to reduce the barrier that complexity poses to further growth. In other words, autonomic computing refers to the self-managing characteristics of distributed computing resources, adapting to unpredictable changes whilst hiding intrinsic complexity to operators and users. An autonomic system makes decisions on its own, using high-level policies; it will constantly check and optimize its status and automatically adapt itself to changing conditions. As widely reported in literature, an autonomic computing framework might be seen composed by Autonomic Components (AC) interacting with each other [1]. An AC can be modeled in terms of two main control loops (local and global) with sensors (for self-monitoring), effectors (for self-adjustment), knowledge and planer/adapter for exploiting policies based on self- and environment awareness. Driven by such vision, a variety of architectural frameworks based on “self-regulating” autonomic components has been recently proposed. A very similar trend has recently characterized significant research work in the area of multi-agent systems. However, most of these approaches are typically conceived with centralized or cluster-based server architectures in mind and mostly address the need of reducing management costs rather than the need of enabling complex software systems or providing innovative services. Autonomy-oriented computation is a paradigm proposed by Jiming Liu, in 2001 that uses artificial systems imitating social animals' collective behaviours to solve hard computational problems. For example, ant colony optimization could be studied in this paradigm.[1] |
| Autonomous System | One network or series of networks that are all under one administrative control. An autonomous system is also sometimes referred to as a routing domain. An autonomous system is assigned a globally unique number, sometimes called an Autonomous System Number (ASN). |
| Availability | A measure of how much time a network or a connection is running. Generally the equation is: Time Running / Time Measured (time running divided by time measured). Thus, if you measured something for 20 minutes and it was only up for 19 of them, you’d have 95% availability. |
| Avast! | avast! Antivirus is an antivirus program developed by ALWIL Software a.s., a company based in Prague, Czech Republic. It was first released in 1988. Avast! is based on a central scanning engine that is certified by ICSA Labs[1] and West Coast Lab's Checkmark process[2] and incorporates anti-spyware technology, also certified by West Coast Lab's Checkmark process,[3] as well as anti-rootkit and self-protection capabilities. It is a multiple recipient of the Virus Bulletin VB100 Award, for detection of 100% of "in-the-wild" viruses,[4] and is a past winner of the Secure Computing Readers' Trust Award.[5] Avast! Free Antivirus is the freeware version of Avast! antivirus software available to Microsoft Windows and Linux users, while Avast! Pro Antivirus is offered to businesses and users that want additional features. Priority updates are delivered automatically using PUSH update technology in Avast! Pro Antivirus. Avast! Pro Antivirus also has a command line scanner and a script blocker. |
| Avatar | An avatar is an online character that represents a person. For example, games like World of Warcraft and the Sims Online allow players to create custom characters, known as avatars. Players can control their avatars and interact with other players in an online world. An avatar may also refer to the icon and username that a user chooses when registering for a website or online discussion forum. The avatar name and image typically shows up next to any contributions the user makes on the website. |
| Avocent | Avocent Corporation (NASDAQ: AVCT) is an information technology products manufacturer headquartered in Huntsville, Alabama. Avocent was formed in 2000 from the merger of the world’s two largest KVM (keyboard, video and mouse) switch manufacturers: Apex and Cybex Computer Products Corporation. Product Ranges Avocent focuses on out of band infrastructure management solutions within 8 major fields: Server Management Power Management Service Processor Management Console Server and KVM Management Desktop Management ITIL market IT Service Management Service Desk |
