Answer - • The Silverlight plug-in is a very lightweight component that is necessary for users to access Silverlight applications. The plug-in download and install takes only a few moments, and do not take up much hard drive space. • The Silverlight plug-in is responsible for accessing the Silverlight object in the Web page, downloading and accessing the XAP package, setting up the program environment, and beginning execution of the application. • When a Web page containing a Silverlight application is displayed, the user should be given a link to download the plug-in from Microsoft if the plug-in is not already installed.