Boolean operators are logical functions that describe a relationship between two lists of items.
They can be thought of as mathematical signs. We use Boolean terms to establish parameters for conducting keyword searches. When used in combination with each other, they enable the user to reduce the number of matches to a more manageable level by narrowing the range of possible matches. AND The term AND limits a search by requiring each term to be present. OR results in a larger set of matches, because it calls for a broader range of information.