What are plug-ins?

Plug-ins are software modules that add to the functionality of an application. Many applications make use of them, including Eudora, Photoshop, and web browsers like Firefox and Internet Explorer.

Plug-ins can have many different functions. Web browsers typically use plug-ins to expand the range of formats they can display (e.g., Acrobat documents, QuickTime or Adobe Flash content). When the web browser encounters a format it doesn't support, it looks for a plug-in that does. A plug-in can launch its own viewer, appear within a browser window, appear in an embedded frame (within a window that may also contain HTML), or run in the background. Plug-ins work in similar ways with other kinds of programs.

How you install a plug-in depends on both the parent application and the plug-in itself. In many cases, the directory or folder where you place your plug-in(s) may have an installer. For more information, consult the documentation for both the plug-in and the application.

For more information about specific plug-ins, visit one of these sites:

• Firefox
• Mozilla
• Thunderbird
• Adobe Photoshop and other Adobe products
• BBEdit (text editor)

Note: Not all plug-ins are compatible with all browsers. Always check a plug-in's documentation before trying to use it with your web browser.

Also see:

• Can I put a file on the web even if it can't be displayed or handled by a web browser?
• What do some of the graphics format file extensions stand for?
• What is a PDF file?