What do you understand by the term Silverlight Run Time?

Silverlight Run Time is a plugin utilized for different browsers in order to support various Silverlight enabled applications. In case the Silverlight Run Time is not installed then the browsers cannot run Silverlight elements from the browser. One can set up the Silverlight tag in such a manner that the browser will automatically notify the user to download and install the plugin required by Silverlight for the application to be launched and run smoothly by the browser.