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.
Search engines vary on how proximity is performed. This is especially important in search engines that do not automatically look for plurals, for example, educator and educators. Punctuation for wildcards varies. Read the database help section. Again, search engines are not standardized.