What is the purpose of a "subpoena"?

The purpose of a subpoena is to formally request an individual's attendance at a judicial proceeding, such as a trial or deposition. This legal document is used to compel witnesses to provide testimony or produce evidence relevant to a case, ensuring that the necessary parties are present to assist in the adjudication of the matter. This is crucial for the fair administration of justice, as it enables the court to properly assess all relevant information.

The other options offered do not accurately represent the function of a subpoena. Issuing a search warrant deals with the authorization for law enforcement to search a specific location for evidence, which is a separate legal process. Filing an appeal is a mechanism to contest a court's decision, and settling a dispute outside of court involves negotiation or mediation process, both of which are distinct from the purpose of a subpoena.