What is webmaster tool

What is webmaster tool:-
"Webmaster Tools that can help with your keyword research and onsite optimization"

How to add site in webmaster tool:- First of all we open a link (https://www.google.com/webmasters/tools), after that just signup thorugh your gmail account . then login. you find a button on the dashboard "Add a site"just click on this button and enter the URL of your site and continue.

webmaster give us a verification file just download in your site and upload .then click on the verify button.
After few minute u will see , your site added in the webmaster tools.

Now go on the dashboard and click on the site link.Webmaster Tools that can help with your keyword research and onsite optimization, both of which can be found under “Your site on the web” on the left hand navigation.
some parts of the "your site on the navigation":-
1)Search queries
2)link to your site
3)Keywords
4)Internal links
5) Subscriber Stats

Search Queries:-Webmaster Tools that can help you find and target keywords is the “Search queries” report.and in this report you can also find the search results (impressions) and visitors to your site (clicks).

Keywords:-Which keyword are mostly used in your sites, webmaster tools put on the top of our keyword list.