About plug-ins
A plug-in is one of a set of software modules that integrate into Web browsers to offer a range of interactive and multimedia capabilities.
Some plug-ins occupy a space on a Web page, as in the case of certain MPEG video players. Those plug-ins may have a display area as well as video controls for playing, pausing, or rewinding, for example.
Other plug-ins, like some MIDI players, don't occupy any space on a Web page. Plug-ins such as these may, for example, begin playing music as soon as you load a Web page, but have no "on" or "off" buttons.
Many developers create their own plug-ins to enable software to run in a Web browser. Because developers may follow different conventions when designing plug-ins, some plug-ins might behave differently, depending on browser types and versions.
Important Security vulnerabilities in external files or controls may extend to Web pages that use those items. For example, external style sheets (files with a .css extension), script files (files with a .js extension), custom ASP.NET controls, or other items, may pose a security risk. Be sure your style sheets, add-ins, themes, executables, scripts, controls, or other files come from trusted sources.