There are several types of court summons. In some cases, individuals simply receive a summons to appear in court. However, a subpoena duces tecum is a demand that the individual take part in a production of evidence. That production of evidence may include documents or some other form of evidence that the individual is required to bring to court.
For example, during child support cases, a subpoena duces tecum may demand that both parents bring bank statements, pay stubs and other materials which apply to finances. These documents may be used to help the judge to determine the proper amount of child support payments which should be awarded.
A production of evidence subpoena may include very specific documentation, as well as the appearance of the individual.