Glossary

When a computer or other device is not turned on or connected to other devices, it is said to be "offline." This is the opposite of being "online," when a device can readily communicate with other devices. For example, if you try to print to your printer and you get one of those frustrating errors saying, "The specified printer could not be found," the printer is probably offline. You should check to see if the printer is connected properly and, yes, turned on as well.

Offline can also mean not being connected to the Internet. When you disconnect from your ISP or pull out the Ethernet cable from your computer, your computer is offline. Some programs, such as Web browsers and e-mail programs, have an option to "Work Offline." This option disables the program's network connection, meaning no data can be transmitted to or from the computer. This option was more useful when most people used dial-up connections. They didn't want their computer automatically dialing their ISP whenever a program tried to access the Internet. However, since most people now have "always on" connections such as DSL and cable modems, there usually is no reason to work offline.

Stands for "Object Linking and Embedding." It can be pronounced as "O-L-E," or "Oh-lay!" if you are feeling Spanish. OLE is a framework developed by Microsoft (way back in Windows 3.1) that allows you to take objects from a document in one application and place them in another. For example, OLE may allow you to move an image from a photo-editing program into a word processing document.

The OLE technology was initially created to allow the linking of objects between "compound documents," or documents that support multiple types of data. Microsoft has since developed OLE into a wider standard, known as the Component Object Model (COM). COM is supported by Mac, Unix, and Windows systems, but is primarily used with Microsoft Windows. The COM framework is the foundation of ActiveX, which allows developers to create interactive content for the Web.

In general, when a machine is "online," it is turned on and connected to other devices. For example, when a network printer is online, computers connected to that network can print from it. Other devices, such as scanners, video cameras, audio interfaces, and others are said to be online when they are running and connected to a computer system.

Recently, however, the term "online" usually means being connected to the Internet. The connection can be through a phone line, using a dial-up or DSL modem, a cable line via a cable modem, or through a wireless connection. A computer can also be online via a connection to a computer network. Technically, computers that are on a network are online even if they are not connected to the Internet. But most networks are routed to a T1 line or other Internet connection anyway. When a computer or other device is not online, it is said to be offline.

When a software program is open source, it means the program's source code is freely available to the public. Unlike commercial software, open source programs can be modified and distributed by anyone and are often developed as a community rather than by a single organization. For this reason, the phrase "open source community" is commonly used to describe the developer of open source software development projects.

Since the source code of an open source program can be modified by anyone, it makes sense that the software is also free to download and use. The terms of use are often defined by the GNU General Public License, which serves as the software license agreement (SLA) for many open source programs. Open source software development projects are often funded by donors with an interest in the project, by user donations, or through advertisements. Some developers also generate revenue by selling documentation and help manuals for the software. Other projects are funded by no more than a collective desire of developers to create a great program.

Since open source software is free to use, there is typically no technical support included with the software. Instead, users may need to rely on Web forums and user discussions to report bugs or get answers to their questions. Fortunately, the most popular open source programs have an abundance of helpful resources available on the Web. Some of the most well-known open source projects include the Linux operating system, the Mozilla Firefox Web browser, and the OpenOffice.org productivity suite. Each of these projects have been developed by a community of developers and have gained levels of popularity that rival their commercial counterparts.

OpenGL, or the Open Graphics Library, is a 3D graphics language developed by Silicon Graphics. Before OpenGL was available, software developers had to write unique 3D graphics code for each operating system platform as well as different graphics hardware. However, with OpenGL, developers can create graphics and special effects that will appear nearly identical on any operating system and any hardware that supports OpenGL. This makes it much easier for developers of 3D games and programs to port their software to multiple platforms.

So how exactly does OpenGL work? When programmers write OpenGL code, they specify a set of commands. Each command executes a drawing action or creates a special effect. Using hundreds or even thousands of these OpenGL commands, programmers can create 3D worlds which can include special effects such as texture mapping, transparency (alpha blending), hidden surface removal, antialiasing, fog, and lighting effects. An unlimited amount of viewing and modeling transformations can be applied to the OpenGL objects, giving developers an infinite amount of possibilities.

A set of instructions that tell a computer on how to operate when it is turned on. It sets up a filing system to store files and tells the computer how to display information on a video display. Most PC operating systems are DOS (disc operated system) systems, meaning the instructions are stored on a disc (as opposed to being originally stored in the microprocessors of the computer). Other well-known operating systems include UNIX, Linux, Macintosh, and Windows.

Data that come out of a computer device. For example, information displayed on the monitor, sound from the speakers, and information printed to paper.