By default the search engine tries to locate pages which have
exact matches for all of the words entered in your search
query. If that fails, it then tries to locate pages which
contain any words in your search query. If that happens a
short message is displayed at the top of the search results
indicating this has been done.
Most search engines offer several ways to modify the default search behaviour
by using qualifiers and/or general web settings. Boolan search is common to many