A citation is a formal reference that tells readers where information came from. When you write a research paper and mention that giraffes can run 35 miles per hour, you need a citation showing which book, website, or expert provided that fact. Without the citation, readers can't check if the information is accurate or learn more about the topic.

Citations typically include the author's name, the title of the source, and when it was published. Your teacher might ask you to put citations in a list at the end of your paper called a bibliography or works cited page. Different subjects use different citation styles: scientists often use one format, while historians use another.

The word has another meaning in law and everyday life. A citation can also be an official notice that someone broke a rule. A police officer might issue a citation for speeding or parking illegally. A student might receive a citation for breaking school rules. In both cases, the citation is a formal written record of what happened.

Citations give credit to the people whose ideas and research you're using, and they help your readers trace information back to its source.