A Boolean search allows someone to search with words such as AND, OR, or NOT to search for more relevant items. When using AND, the search would need to include both of the keywords, while OR would mean that it has to include only one or the other of the key words, but could also include both. The search "German shepherds AND rescue OR service" would therefore likely include things about rescue German shepherds and service German shepherds or rescue and service German shepherds. This would eliminate results that would include German shepherds as a general dog breed or a pet. That is why the Boolean logic in searching is helpful.