Any court document carrying the court seal or clerk's signature, that must be properly served on (that is, given to) the party or witness named in the document, is called a process document or process. A subpoena--a document requiring the appearance of a person or the production of documents at a hearing--and a summons are examples of court process. Rules as to who can serve process and how it must be done vary. Some states allow only sheriffs, marshals and constables to serve process. Other states also authorize registered process servers (often private investigators), and a few states allow service by anyone 18 or over who is not a party to the case.
So denominated because it proceeds or issues forth in order to bring the defendant into court, to answer the charge preferred against him, and signifies the writ or judicial means by which he is brought to answer.
In the English law, process in civil causes is called original process, when it is founded upon the original writ; and also to distinguish it from mesne or intermediate process, wliich issues pending the suit, upon some collateral interlocutory matter, as, to summon juries, witnesses,, and the like; mesne process is also sometimes put in contradistinction to final process, or process of execution; and then it signifies all process which intervenes between the beginning and end of a suit.
In criminal cases that proceeding which is called a warrant, before the finding of the bill, is termed process when issued after the indictment has been found by the jury.
The word process in the 12th section of the 5th article of the constitution of Pennsylvania, which provides that "the style of all process shall be The Commonwealth of Pennsylvania," was intended to refer to such writs only as should become necessary to be issued in the course of the exercise of that judicial power which is established and provided for in the article of the constitution, and forms exclusively the subject matter of it.
By this term is generally understood any writ issued in the course of a suit between the original process and execution.By this term is also meant the writ or proceedings in an action to summon or bring the defendant into court, or compel him to appear or put in bail, and then to hear and answer the plaintiffs claim.