What is Microsoft Silverlight and why do I need it?

Since I have installed MS Silverlight there are too many pop ups and unnecessary advertisements. I do not know about the Pros but these are the Cons it have.

I checked out http://www.silverlight.net/, but there's no information about whether I need Silverlight or not. It says it's a development tool. So only developers need it? It got downloaded and installed as part of the Windows automatic updates, but it's the third largest application installed on my computer, it's been there for years and I don't know that I've ever used it.

Okay, here's my problem, as small as it may be.

I am on a Mac laptop, it runs Safari as it's internet browser.  The BING bar that appears on the top of the MSN homepage is obscurring the content just below.  (flipping 8-10 news stories at a time)  You just can't read the headlines.

Considered solution?  Making Google my home page.

The other thing is, I get a UPDATE notification after I click on something that requires a password, ei... my bank, Google, my phone carrier.  So, as you're typing in your password this little annoying box pops up and asks if you'd like to update SILVERLIGHT?  If you're not looking at the screen, and hit return, it begins to download.  Pretty sneaky.  One of the reasons that drove me away from Microsoft & Windows to start with.

I think I orignally downloaded it as it came highly recommended, but had vauge to nill search results.  I just downloaded it to see what it was.  I haven't downloaded any updates since.

So, if you have, or have had this problem, BE AWARE!  I would NOT recommend Silverlight to anyone.

BTW-For What its worth, I've been running this Macbook Pro 15" (with Mac OS 10-ver 10.6.8) for almost 4 years without one lousy hick-up or burp.  No BLUE WNDOWS OF DEATH, VIRUSES, or any other common Windows ailments. Never once has it failed to come on and do anything I've asked up it.  Long live Macs - the other comptuer!

Later,