If you enable this policy, a "Search the Internet" link is shown when the user performs a search in the start menu search ...

If you enable this policy, a "Search the Internet" link is shown when the user performs a search in the start menu search box.  This button launches the default browser with the search terms.

If you disable this policy, there will not be a "Search the Internet" link when the user performs a search in the start menu search box.
          
If you do not configure this policy (default), there will not be a "Search the Internet" link on the start menu.