The term process serve is mostly used and commonly known in the legal field and so it is a term that is hardly known to general public and those serving in other industries.
Most business professionals, at some point, will require contractual or court documents to be delivered to a given company or individual by a professional process server in accordance with specified legal requirements.
At any time a citizen could be summoned to a court. This is done by delivering a legal notice to the individual or the company - whoever is the defendant in a particular case.