Use case

Post date: Jun 02, 2010 5:54:1 PM

A use case in software engineering and systems engineering is a description of a system’s behavior as it responds to a request that originates from outside of that system. In other words, a use case describes "who" can do "what" with the system in question. The use case technique is used to capture a system's behavioral requirements by detailing scenario-driven threads through the functional requirements.

http://en.wikipedia.org/wiki/Use_case