Computer Terms Beginning with "A"

[MysteRy]

AIX

Stands for "Advanced Interactive Executive," though some Linux fans have been known to refer to it as "Ain't UNIX." AIX is an operating system developed by IBM and is in fact Unix-based. It is typically used for enterprise servers and comes with a robust set of security options such as Kerberos V5 network authentication and dynamic secure tunnel authentication. AIX allows the system administrator to divide memory, CPU, and disk access between various jobs. The system supports IBM's 64-bit POWER processor and is backwards-compatible with 32-bit applications. It also runs most Linux applications (after recompiling them) and has full support for Java 2. If all that jargon makes no sense to you, relax -- AIX is not your typical consumer operating system. It is mainly used for servers in large businesses where IT geeks get to work with it.

[MysteRy]

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.

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Algorithm

An algorithm is a set of instructions, sometimes called a procedure or a function, that is used to perform a certain task. This can be a simple process, such as adding two numbers together, or a complex function, such as adding effects to an image. For example, in order to sharpen a digital photo, the algorithm would need to process each pixel in the image and determine which ones to change and how much to change them in order to make the image look sharper.

Most computer programmers spend a large percentage of their time creating algorithms. (The rest of their time is spent debugging the algorithms that don't work properly.) The goal is to create efficient algorithms that do not waste more computer resources (such as RAM and CPU time) than necessary. This can be difficult, because an algorithm that performs well on one set of data may perform poorly on other data.

As you might guess, poorly written algorithms can cause programs to run slowly and even crash. Therefore, software updates are often introduced, touting "improved stability and performance." While this sounds impressive, it also means that the algorithms in the previous versions of the software were not written as well as they could have been.

[MysteRy]

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.

[MysteRy]

Android

Android is Google's mobile operating system (OS) that is used by several smartphones, such as the G1, Droid, and Nexus One. Android is open source, meaning it is not linked to a specific cell phone manufacturer or service provider. The Android OS also supports third-party applications, which can be downloaded from Android Market, Google's online software store.

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ANSI

Stands for "American National Standards Institute." ANSI's primary goal is to enhance the global competitiveness of U.S. businesses and to improve the American quality of life by promoting and facilitating voluntary consensus standards and conformity assessment systems. "Voluntary" standards are driven by marketplace needs rather than regulated by the government. "Conformity assessment systems" test the compliance of a product or service to a standard. ANSI does not itself develop standards or conduct tests, rather it facilitates this work by "accrediting" (i.e., recognizing) qualified groups with appropriate expertise. The Institute is the official U.S. representative to the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). ANSI is a private, nonprofit membership organization with offices in Washington, DC and New York City.

If you'd like more information about ANSI, there's no better place to visit than ANSI's Web site. There you'll find more information about ANSI and what they do, as well as the latest news on national and international standards. Check it out!

[MysteRy]

Antivirus

Example: "You should run an antivirus program to make sure your computer isn't infected."

Antivirus (also written "anti-virus" or simply "AV") is software designed to prevent, detect, and remove viruses from a computer. Once installed, most antivirus programs run in the background, scanning new files for viruses and performing regular system checks. You can also use an antivirus utility to scan individual files or folders directly. The software operates by checking files against a database of virus definitions, which contain signatures of known viruses. If a file contains a virus, the antivirus program will typically quarantine the file, making it inaccessible (and therefore removing the threat). It may also mark the file for deletion.

While antivirus software primarily scans for viruses, most modern antivirus programs also scan for other types of malware. This includes trojan horses, worms, spyware, and adware. Many antivirus programs are now included as part of "internet security" suites, which offer additional types of system protection, such as customizable firewalls, website blocking, and port monitoring.

[MysteRy]

API

Stands for "Application Program Interface," though it is sometimes referred to as an "Application Programming Interface." An API is a set of commands, functions, and protocols which programmers can use when building software for a specific operating system. The API allows programmers to use predefined functions to interact with the operating system, instead of writing them from scratch.

All computer operating systems, such as Windows, Unix, and the Mac OS, provide an application program interface for programmers. APIs are also used by video game consoles and other hardware devices that can run software programs. While the API makes the programmer's job easier, it also benefits the end user, since it ensures all programs using the same API will have a similar user interface.

[MysteRy]

Apple

Apple is the company that makes Macintosh computers, such as the iMac, Mac mini, MacBook, MacBook Air, MacBook Pro, and Mac Pro. Apple also makes several personal electronic devices, including the iPod, iPhone, and iPad.

While Apple is most known for its hardware devices, the company also develops a wide range of software. Examples include the Mac OS X operating system, iLife, iWork, and several professional media applications, such as Aperture, Logic Studio, and Final Cut Studio.

Apple has also expanded its reach online with the iTunes Store, App Store, and the new Mac App Store. These services allow you to download media and applications directly to your computer. Apple also has over 300 retail stores worldwide, which offer Apple products and provide Apple product support.

[MysteRy]

Applet

This a Java program that can be embedded in a Web page. The difference between a standard Java application and a Java applet is that an applet can't access system resources on the local computer. System files and serial devices (modems, printers, scanners, etc.) cannot be called or used by the applet. This is for security reasons -- nobody wants their system wiped out by a malicious applet on some wacko's Web site. Applets have helped make the Web more dynamic and entertaining and have given a helpful boost to the Java programming language.

[MysteRy]

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.

[MysteRy]

Archie

Archie is a program used for finding files stored on FTP (File Transfer Protocol) servers. Archie is not used very much anymore because to use it effectively, you need to know the exact file name you're looking for. Most file searching is now done via the Web with a Web browser like Internet Explorer or Netscape.

[MysteRy]

Archive

Example: "He sent her all the files in a single archive as an e-mail attachment."

An archive contains multiple files and/or folders within a single file. Archives can be saved in several different formats, most of which incorporate file compression to reduce the file size. They are used for consolidating a group of files into a single package. This can be helpful when transferring multiple files to another user or when backing up data.

In order to open the files contained in an archive, they must first be extracted using a file extraction utility. If the archive is compressed, it must be decompressed before the files can be extracted. Most file decompression programs perform both of these operations automatically.

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ARP

Stands for "Address Resolution Protocol." ARP is a protocol used for mapping an IP address to a computer connected to a local network LAN. Since each computer has a unique physical address called a MAC address, the ARP converts the IP address to the MAC address. This ensures each computer has a unique network identification.

The Address Resolution Protocol is used when information sent to a network arrives at the gateway, which serves as the entrance point to the network. The gateway uses the ARP to locate the MAC address of the computer based on the IP address the data is being sent to. The ARP typically looks up this information in a table called the "ARP cache." If the address is found, the information is relayed to the gateway, which will send the incoming data to the appropriate machine. It may also convert the data to the correct network format if necessary.

If the address is not found, the ARP broadcasts a "request packet" to other machines on the network to see if the IP address belongs to a machine not listed in the ARP cache. If a valid system is located, the information will be relayed to the gateway and the ARP cache will be updated with the new information. By updating the ARP cache, future requests for that IP address will be much quicker. While this may seem like a complex process, it usually takes only a fraction of a second to complete. If only it was just as easy to find old receipts when you need them.

[MysteRy]

Array

An array is a data structure that contains a group of elements. Typically these elements are all of the same data type, such as an integer or string. Arrays are commonly used in computer programs to organize data so that a related set of values can be easily sorted or searched.

For example, a search engine may use an array to store Web pages found in a search performed by the user. When displaying the results, the program will output one element of the array at a time. This may be done for a specified number of values or until all the values stored in the array have been output. While the program could create a new variable for each result found, storing the results in an array is much more efficient way to manage memory.

The syntax for storing and displaying the values in an array typically looks something like this:

arrayname[0] = "This ";
arrayname[1] = "is ";
arrayname[2] = "pretty simple.";

print arrayname[0];
print arrayname[1];
print arrayname[2];

The above commands would print the first three values of the array, or "This is pretty simple." By using a "while" or "for" loop, the programmer can tell the program to output each value in the array until the last value has been reached. So not only do arrays help manage memory more efficiently, they make the programmer's job more efficient as well.