front end

Free On-line Dictionary of Computing

1.An intermediary computer that does set-up and filtering for another (usually more powerful but less friendly) machine (a "back end").

2.Software that provides an interface to another program "behind" it, which may not be as user-friendly. Probably from analogy with hardware front-ends that interfaced with mainframes. [Jargon File]

The Jargon File

1.An intermediary computer that does set-up and filtering for another (usually more powerful but less friendly) machine (a back end).

2.What you're talking to when you have a conversation with someone who is making replies without paying attention. “Look at the dancing elephants!” “ Uh-huh.” “Do you know what I just said?” “Sorry, you were talking to the front end.”

3.Software that provides an interface to another program ‘behind’ it, which may not be as user-friendly. Probably from analogy with hardware front-ends (see sense 1) that interfaced with mainframes.