Boolean operators are terms you can use to narrow or broaden your search in a database, library catalog or Google Scholar. The three basic operators are: AND, OR, and NOT.
Use the operator "AND" in a search to:
Search String: Anxiety AND "college students" AND alcohol
The search above tells the database that you want each article in your results to mention ALL the search terms. This narrows your results because all the terms must be present instead of any articles about anxiety, or college students, or alcohol.
Search String: Racism AND elections AND "United States"
The venn diagram below demonstrates that AND is the intersection of all your search terms - thus it narrows your search.
Use the operator OR to:
Search String: College students OR university students OR undergraduates OR graduate students
The example above will broaden your search because it will pull up articles with ANY of those terms present.
Search String: Feminism OR Gender inequality OR women's rights
Use the operator NOT to:
Search String: Participation AND Democracy NOT "United States"
This tells the database to pull up results about participation and democracy but to exclude any articles that are about participation and democracy specifically in the United States.