By default, this search operates under the assumption that you want the results to contain all search words.  If you wish to negate this functionality, you can do this by using the OR operator.  Using the OR operator, you can specify certain sets of words, of which, only one set has to have all of its search words found.

For example, a search for: health OR exercise program , Will return results that contain health, exercise program, or both.  If you want to match an exact phrase, you can do so by putting the search string in quotes.  

For example, a search for: "Light Program" inline skating , Will only return results that contain the exact phrase "Light Program" and the words inline skating.

If you would like to pick only results that don't contain a certain keyword, you may do so by using the subtraction operator.

For example: a search for: "inline skating" -running , Will only return pages that contain the phrase  "inline skating" that also do not contain the word running.

You can use quotes ("), "and", "or", the minus sign (-) as well as the plus sign (+), to more precisely define your search.

For further help with searching visit searchenginewatch.