Section 1. Subpoena and Subpoena Duces Tecum. —

Subpoena is a process directed to a person requiring him to attend and to testify at the hearing or the trial of an action or at any investigation conducted under the law of the Philippines, or for the taking of his deposition. It may also require him to bring with him any books, documents, or other things under his control, in which case it is called a subpoena duces tecum.