The Robots Exclusion Protocol includes the following exclusion attributes:

• NOINDEX tag tells the Google bot not to index a specific page;
• NOFOLLOW tag tells  the Google bot not to follow the links on a specific page;
• NOARCHIVE tag tells  the Google bot not to store a cached copy of the page;
• NOSNIPPET tag tells  the Google bot not to show a snippet under your Google listing.

Exclusion can be implemented through the robots.txt file or the meta of a selected page using the protocol:

<meta name='robots' content='nofollow' />

For a more detailed explanation see the Robots Exclusion Protocol definition on Google.