All parties facing legal action must be properly notified by a procedure called service of process. Service of process occurs when documents pertaining to legal action are delivered to a party either the plaintiff or the defended. Proper service can occur by either personally serving a party by handing them the document or documents, or by substitute service by serving a person in the same house or business as the party. Once the documents are delivered, the server must provide proof of service port affidavit of service which is typically filed with the court upon completion of service. Many states require document delivery to be done by a professional process server — that is a person licensed to serve documents.