Amazing video by Google :
We are assuming free-download-zone.com as a phrase. and I will give example on this phrase : 1. "free-download-zone.com" - It will search exactly the match for free-download-zone.com . Use (" ") for exact match. Useful when u r finding a song's lyrics or any book. 2. Idm site:free-download-zone.com - It will search Idm only in the site free-download-zone.com . It is useful for the site owners to make search in their own site only. 3. download zone -free : It will exclude the "free" word for search. (-) sign will exclude the results which comes with "free". It means it will search only for free download without having free. You can also use it with site: option to exclude site like idm -internetdownloadmanager.com . It will not show the result from the given site. 4. idm OR free - "OR" is used to specify the search to only show the search which contains any of the both word. Anyways your results would typically show only pages that match both terms if you are not specifying OR.