Boolean operators use AND, OR, NOT to limit or expand a search. (Note the capitalization. Many databases require operators to be in all caps, as do search engines like Google, which also allows for Boolean based searches.)
In other words, the search results will contain search term X and search term Y.
In other words, the search results will contain search term X or search term Y or both.
In other words, the results will not contain search term X.
Boolean operator searches can be simple, e.g., Moose AND Elk; Moose NOT Elk. Or they can be more complex and nuanced when combining operators and use parentheses, e.g., (Caribou AND Elk) NOT Moose; (Moose OR Elk) NOT Caribou.
Searching by a particular phrase or word combination is one of the most precise ways of searching. This is done by putting a phrase or terms between quotation marks. For example, if you want to search a phrase like bending towards justice, search it as "bending toward justice" or, if you want to make sure the database searches political activism as a single term and not individual words, search "political activism."
Sometimes it is unclear whether quotation marks are needed and sometimes using them can limit a search too much. For this reason, it can be a good idea to experiment by conducting searches with and without them.
