search for: john smith (without quotes) --> returns all users that either have john or smith in the name
search for "john smith" --> returns users which name is "john smith"
search for john joe (without quotes) --> returns all johns and joes
search for "John Smith" Chicago --> returns all john smiths and all users living in Chicago
Same principles for advanced search:
search for city: Boston Chicago --> all users living in either Boston or Chicago
search for city: New York --> all users living in any city that has contains either New or York
search for city: "New York" --> all users living in New York