There are two functions in Webmaster Tools which you may find interesting and informative.
The functions are listed below with detailed steps.
To prevent all robots from indexing a page on your site, place the following meta tag into the <head> section of your page:
<meta name="robots" content="noindex">
To allow other robots to index the page on your site, preventing only Google's robots from indexing the page:
<meta name="googlebot" content="noindex">
"Nofollow" provides a way for webmasters to tell search engines "Don't follow links on this page" or "Don't follow this specific link."
Originally, the nofollow attribute appeared in the page-level meta tag, and instructed search engines not to follow (i.e., crawl) any outgoing links on the page. For example:
<meta name="robots" content="nofollow" />