Read the HELP screens. They give examples as to how to manipulate each engine. Both these concepts should appear. OR is best used for synonyms. Most engines allow use of quotations marks to search for an exact phrase, instead of the words appearing in any order.
Search engines amass their store of websites by registration or automatic searching.
A person that creates a website can go to a search engine and submit the new website address. It then becomes part of the engine's base on which to search. The engines also send out websitefinders called robots to look for new websites. When creating a website one can tell the robot what to use to index the site so it can be found later when potential visitors are searching. Websites come and go everyday with remarkable speed.