A summons is a court form that orders the person named in it to appear in court. A summons is usually thought of as the document that accompanies a complaint – the document by which one person describes the basis for a lawsuit against another.
The summons is delivered with the complaint and requires that the person sued answer or otherwise respond to the complaint within thirty days. If no timely response is filed to the lawsuit, the court can determine that the person who filed the lawsuit has won the lawsuit.
A summons of a different type is also used to require people to appear in court to serve on a jury. This is called a juror summons.