Glossary
Subpoena
A court order requiring a person to appear, testify, or produce documents. Subpoenas can be served on parties or non-parties, and ignoring one can result in being held in contempt of court.
There are two main flavors: a regular subpoena requires the person to show up and testify (e.g., at a deposition or trial), and a subpoena duces tecum requires them to bring specific documents.
Non-parties (people not named in the lawsuit) can be subpoenaed. They have rights too: they can move to quash the subpoena if it's overbroad, asks for privileged material, or imposes undue burden.
Ignoring a properly served subpoena is contempt of court. Don't ignore one. If you've been served and don't think you should have to comply, talk to a lawyer or move to quash before the deadline.