Glossary

This book includes a glossary so that you can find terms and acronyms easily. It has several important features you need to know about. First, every acronym in the entire book appears here ”even if there's a better than even chance you already know what the acronym stands for. (The book does exclude common acronyms such as units of measure and most file extensions because these terms are easy to find in other sources, and most people know what they mean.) This way, there isn't any doubt that you'll always find everything you need to use the book properly.

Second, these definitions are specific to the book. In other words, when you look through this glossary, you're seeing the words defined in the context in which they're used in this the book. This might or might not always coincide with current industry usage since the computer industry changes the meaning of words so often.

Finally, I've used a conversational tone for the definitions here in most cases. This means that the definitions might sacrifice a bit of puritanical accuracy for the sake of better understanding. The purpose of this glossary is to define the terms in such a way that there's less room for misunderstanding the intent of the book as a whole.

What to Do If You Don't Find It Here  

While this glossary is a complete view of the words and acronyms in the book, you'll run into situations when you need to know more. No matter how closely I look at terms throughout the book, there's always a chance I'll miss the one acronym or term that you really need to know. In addition to the technical information found in the book, I've directed your attention to numerous online sources of information throughout the book and few of the terms the Web site owners use will appear here unless I also chose to use them in the book. Fortunately, many sites on the Internet provide partial or complete glossaries to fill in the gaps:

• Acronym Finder http://www.acronymfinder.com/

• Free Online Dictionary Of Computing (FOLDOC) http://nightflight.com/foldoc/

• Microsoft Encarta http://encarta.msn.com/

• TechDis Accessibility Database http://www.niad.sussex.ac.uk/glossary.cfm

• Webopedia http://webopedia.internet.com/

• yourDictionary.com http://www.yourdictionary.com/

Let's talk about these Web sites a little more. Web sites normally provide acronyms or glossary entries ”not both. An acronym site only tells you what the letters in the acronym stand for, it doesn't provide definitions to explain what the acronym means in everyday computer use. The two extremes in this list are Acronym Finder (acronyms only) and Webopedia (full-fledged glossary entries).

Acronym Finder has the advantage of providing an extremely large list of acronyms from which to choose. At the time of this writing, the Acronym Finder sported 164,000 acronyms. Many of the acronyms have nothing to do with computers ”making Acronym Finder an excellent resource for acronyms of all types.

Most of the Web sites that you'll find for computer terms are free. In some cases, such as Microsoft's Encarta, you have to pay for the support provided. However, these locations are still worth the effort because they ensure you understand the terms used in the jargon-filled world of computing.

Webopedia has become one of my favorite places to visit because it provides encyclopedic coverage of many computer terms and includes links to other Web sites. I like the fact that if I don't find a word I need, I can submit it to the Webopedia staff for addition to their dictionary, making Webopedia a community supported dictionary of the highest quality.

One of the interesting features of the yourDictionary.com Web site is that it provides access to more than one dictionary and in more than one language. If English isn't your native tongue, then this is the Web site of choice.

A

Accessibility

A measure of a user's ability to interact with an application. For example, applications should provide both mouse and keyboard access to every control to ensure the user can reach the control for use. In addition to direct user support, an application should support all devices without providing specialized support for a particular device unless necessary. A Braille input device should receive no special treatment beyond that required for a keyboard.

Active Server Pages (ASP)

A special type of scripting language environment used by Windows servers equipped with Internet Information Server (IIS). This specialized scripting language environment helps the developer create flexible Web applications that include server scripts written in a number of languages such as VBScript, JavaScript, JScript, and PerlScript. The use of variables and other features, such as access to server variables , helps the developer create scripts that can compensate for user and environmental needs as well as security concerns. ASP uses HTML to display content to the user. Recent extensions to ASP in the form of Active Server Pages eXtended (ASPX) provide a broader range of application support functionality, improved debugging, new features such as "code behind," and improved performance. Note that you need to install the .NET Framework to use ASPX pages.

ActiveX Data Object (ADO)

A local and remote database access technology that relies on Object Linking and Embedding - DataBase (OLE-DB) to create the connection. ADO is a set of "wrapper" functions that make using OLE-DB and the underlying OLE-DB provider easier. ADO is designed as a replacement for Data Access Objects (DAO) and as an adjunct to Open Data-Base Connectivity (ODBC).

ADO

See also ActiveX Data Object (ADO).

API

See also Application Programming Interface (API).

Applet

A helper or utility application that normally performs a task within a specialized environment such as a browser or as part of an operating system. Java is one of the most commonly used languages for creating applets for browser applications. Another example is the Control Panel applications used to configure Windows. In both cases, the applications perform a limited task within a specialized environment.

Application

The complete program or group of programs. An application is a complete environment for performing one or more related tasks .

Application Programming Interface (API)

A method of defining a standard set of function calls and other interface elements. It usually defines the interface between a high-level language and the lower level elements used by a device driver or operating system. The ultimate goal is to provide some type of service to an application that requires access to the operating system or device feature set.

Array

A structure that acts like an in-memory database. An array provides random or sequential access each element by number (also called a subscript). Arrays normally contain a single dimension. In some cases, arrays provide multidimensional access to data. A multidimensional array has the same number of elements in each sub-array in a given dimension. Jagged arrays treat each dimension as a separate sub-array, which means that each sub-array can contain a different number of elements.

ASP

See also Active Server Pages (ASP).

AT&T

American Telephone and Telegraph

Attribute

An attribute expresses some feature peculiar to an object. When referring to a database, each field has an attribute that expresses what type of information it contains, the length of the field, the field name , and the number of decimals. When referring to a display, the attribute expresses pixel color , intensity, and position. In programming, an attribute can also specify some type of object functionality, such as the method used to implement security.