What is Microsoft Silverlight on a Mac And do I need it?

Some sites require Silverlight to work correctly. Microsoft has discontinued Silverlight so less and less sites are require it now.

I would uninstall Silverlight and see if sites you use ask you to install Silverlight.

A few obscure applications require it. I tried installing Canon camera software on my computer and it wanted to install Silverlight. I denied it and only part of the Canon software now works (the image browser but not the editor).