OR can be used for synonyms to a concept, for instance adolescent OR teenage violence. A comma or just a space can indicate OR as well as the word. NOT is used to eliminate things from a broader category. For instance, violence NOT domestic will find of all kinds violence except domestic violence. The computer will match chad with either dimpled or pregnant to pull up relevant hits.
Phrases are two or more words that have to be found in an exact order.
Most search engines specify quotation marks around words that must be searched as a phase. Limiting allows the user to select by media type, document type, language, specify certain dates, a domain name and other special criteria. The search engine should return only those hits which meet the specifications. Many search engines provide drop boxes or check boxes with limiting criteria. Proximity refers to the distance between search terms.