A probe is a computer program that operates on its own but is intended to operate with another (generally a larger and principal) computer program, and the purpose of which is to perform some preliminary inquisitive technical matter and report the result thereof to the other principal computer program with which it operates. The corpus is the principal portion of a computer program (or group of computer programs intended to operate together) that may or may not be capable of operating in a self-sufficient manner, but usually intended to operate in conjunction with a probe or other minor computer software product.