MIT
Boolean operators form the basis of mathematical sets and database logic.
They connect your search words together to either narrow or broaden your set of results.
The three basic boolean operators are: AND, OR, and NOT.
Why use Boolean operators?
To focus a search, particularly when your topic contains multiple search terms.
To connect various pieces of information to find exactly what you're looking for.
This video from BrainPop shows how to start finding sources and how one source can point to another.