The OR operator broadens your search results by retrieving records that contain either or both of your search terms or concepts.
- Usually, terms within a concept are combined using the Boolean OR operator.

The AND operator narrows the search results by retrieving records that contain both of your search terms or concepts.
- Usually, different concepts are combined using the Boolean AND operator

The NOT operator narrows the search results by eliminating a specific search term.
- Use the NOT operator with caution. It can eliminate relevant results that happen to mention the term you are "noting" out.
