plug-in

plug-in

Software that is installed into an existing application in order to enhance its capability. For example, plug-ins are widely used in image editing programs such as Photoshop to add some special effect. Plug-ins are added to Web browsers to enable them to support different types of content (audio, video, etc.). The term is widely used for software, but can also refer to a plug-in module for hardware.

Plug-In, Add-On, Extension
Although the terms "plug-in," "add-on" and "extension" are used synonymously, a plug-in implies adding new functionality, whereas add-on and extension imply more of a modification to an existing function. These distinctions are not evident in the literature however. See plug-inless and browser plug-in.

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plug-in [′pləg‚in]

(computer science)

A small software application that extends the capabilities (such as multimedia, audio, or video) of a browser.

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(tool)

plug-in - A file containing data used to alter, enhance, or extend the operation of a parent application program. One of the first uses of this term was in Silicon Beach's SuperPaint application (late 1980s?) for the Macintosh. It had a Plug-ins folder containing different tools and effects. The Netscape Navigator World-Wide Web browser supports plug-ins which display or interpret a particular file format or protocol such as Shockwave, RealAudio, Adobe Systems, Inc. PDF, Corel CMX (vector graphics). The file to be displayed is included in a web page using an EMBED HTML tag. Plug-ins, both commercially and indepently authored, can usually be downloaded for free and are stored locally. Plug-ins come in different versions specific to particular operating systems (Microsoft Windows 3.1, 3.2, and Macintosh are available). Compare applet. Plug-in Plaza. PC Mag Plug-ins.