When a user searches through an index, he is essentially building a query and submitting it to the search engine. If we want a more complex type of query, we can use Boolean operators to refine the search and even extend it.
AND - All the terms joined by "AND" must appear in the pages.
OR - At least one of the terms joined by "OR" must appear in the pages or documents.
NOT - The term or terms following "NOT" must not appear in the pages or documents.
FOLLOWED BY - One of the terms must be directly followed by the other.
NEAR - One of the terms must be within a specified number of words of the other.
Quotation Marks - The words between the quotation marks are treated as a phrase, and that phrase must be found within the document or file.