Plug-In
Plug-in refers to additional software that is required to execute a transaction via a web browser. Thus if the webpage is designed to run with something that is not standard to the browser, the viewer needs to download an additional plug-in. This may be used to run enhanced graphics (Flash), sound (Real Audio) or 3D (Cosmo Player), or other such rich media applications. Before designing a site to require a plug-in, it is important to note how much of your target audience has the additional plug-in, the likelihood of those not having the plug-in downloading it, and whether the design functions without the plug-in (i.e. does the additional feature(s) compliment or replace the information design of the site). As the web browser develops, the requirements of use of plug-ins will diminish, so this is a temporary situation. It is advised not to require the use of plug-ins on the homepage, especially if the information from the plug-in is required to meet the informational goals of the site.