It is your choice, but if you have material information that would aid either the prosecution OR the defense, and choose to withhold it, you may be treated as a "hostile witness" or, even held in contempt of court for withholding evidence.
The purpose of a subpoena is to get someone to come to court to either testify for you or against you. When a person gets this subpoena, they have no choice but to attend the court session.
You need an attorney to subpoena someone in court. This is not something you can do yourself.
Exactly what it means depends on the content of the subpoena. In general terms, a subpoena is a court order to produce evidence, which can include testimony. If the subpoena commands you to appear and testify in court, then you must do so or you can be arrested for contempt of court.
A writ requiring appearance in court to give testimony is called a subpoena.
Subpoena.
summons or subpoena.
A "subpoena duces tecum." directs an individual to come to court and directs that certain items be brought with them. A 'regular' subpoena simply directs the individual to come to court.
That is the correct spelling of the word "subpoena" (a court summons to testify).
A subpoena requires you to appear in court, not go to jail.
If you have an attorney representing you, he or she can create the subpoena and have it served on the witness. If you don't have representation, you must ask the court to issue the subpoena. You may then be required to pay the costs for a process server, constable, or deputy sheriff to serve the subpoena on the witness.
A subpoena is a court order that requires you to be in court.
(I am not a lawyer. This is not legal advice.) The answer almost certainly depends on the rules of civil procedure for the jurisdiction in question. ...but that being said, in many cases the subpoena will need to be signed by either an attorney licensed to practice before that court, or the clerk of court. If so, you can get a blank, signed form from the clerk. Then, when you serve the subpoena, you must generally also file a copy of the subpoena and a "certificate of service" (documenting how and when you served the subpoena) with the court. This is presumably to establish a timeline, in case you need to petition the court to compel enforcement of an unanswered subpoena.