Significance

Microsoft pop-ups that encourage you to install Silverlight are an indication that you do not have this framework already installed on your computer. When your computer tries to run a Silverlight plug-in, it can't, and is prompted to download the framework.

Function

Microsoft Silverlight is a framework that allows browsers to run multimedia content, such as videos, games and animations. Microsoft developed this framework in competition to the Flash framework, and they want as many people to use Silverlight as possible.

Benefits

Installing Silverlight on your computer, as Microsoft wants you to do, will enable you to run multimedia content that has been coded in the Silverlight framework. Microsoft's entire site has animations that use Silverlight to operate, and many other sites are starting to use Silverlight as well.

Prevention/Solution

To make the messages prompting you to install Silverlight go away, download the plug-in that you are prompted to get, and install it on your computer. This will install Silverlight on your computer, making the message pop-ups go away.

Potential

Another reason that Microsoft is pushing Silverlight is because they see it as a superior framework for developing multimedia applications, compared to their competitor, Flash.

Source:

Microsoft to Push Silverlight via Redesigned Website