Can someone explain these "root certificate" updates MS puts out?

[nemt]

What exactly do they do? I've read the wikipedia article, but I still don't really get what they're for.

 

[Chairman Meow]

Root certificates are the encryption keys that your web browser uses for connecting to secure HTTP sites. The point of having the root certificates is that they provide a way for a site to identify itself, using the credibility of the companies that issued the root certificate, such as Verisign, to establish the identity of the site you're connecting to.