Basically this webmaster tools area is a way for you to register domains you own with Google. This gives you the ability to monitor various aspects of your websites.

Now when i say websites, I’m referring to a domain you purchased and have a site running on a server. This will not work with Web 2.0 blogs( at least to my knowledge), such as Blogger, Wordpress.com, etc.

The great thing about this service is it will tell you specifically when Google has visited your website and how many pages it has indexed. It goes even further to show you what pages it was having trouble accessing.

Now this new feature I mentioned, Duplicate Content, is a HUGE issue in Google. One of the many things Google will penalize your websites for is Duplicate Content. If it sees too much of it you are delisted
from the search results until you can fix the problems.

For the longest time you had to dig through your own websites and determine what was being duplicated and what was not. Now with this new tool on the Google Webmaster Tools page you can see, from an
internal stand point, what is considered duplicate content. It tells you exactly where this duplicate content has shown up in both areas, so you can easily remove/change the content to decrease the penalization score with Google.

(hope your not bored by now)

So, now we have gotten rid of the duplicate content on our websites we can now rank higher in Google and for possibly more phrases. Higher rankings equal a better chance at gaining more prospects for your sites
and more prospects equals more money.

Hope I have explained this well enough. This is definitely not the end all explaination of Google Webmaster Tools. It should suffice for the basics.

-Ryan