California Probation Officer Trainee Practice Exam 2025 - Free Probation Officer Practice Questions and Study Guide

The term used to refer to an order that requires a witness to appear in court is "subpoena." A subpoena is a legal document that compels a person to attend a legal proceeding, such as a trial or a deposition, and may also demand the production of evidence. This is an essential tool in the legal system, ensuring that witnesses, who may have pertinent information to a case, are available to testify and provide that information to the court.

In legal contexts, an affidavit is a written statement confirmed by oath or affirmation, but it does not require attendance in court by the person providing the statement. A writ typically refers to a formal order issued by a court, often commanding a person to do or refrain from doing something, but it is not specifically for summoning a witness. A summons, on the other hand, is primarily used to notify a defendant of a legal action against them, requiring their appearance in court, which distinguishes it from a subpoena's function of summoning witnesses. Thus, the correct choice is clearly the subpoena, as it specifically operates to compel a witness to appear before the court.