A referendum is an official vote on a specific issue. It's often part of a larger election.
On many issues, our elected representatives argue, negotiate, and make a law, but sometimes there's a referendum — the issue is put directly to the people for a vote as part of an election. Usually, a referendum is a yes or no question. Smaller groups can have referendums too — like a school system deciding whether or not to have school uniforms or a longer school year.