the side that is forward or prominent; front, forepart
Microsoft Computer Dictionary
n. 1. In a client/server application, the part of the program that runs on the client. See also client/server architecture. Compare back end (definition 1). 2. In applications, software or a feature of software that provides an interface to another application or tool. Front ends are often used to supply a common interface for a range of tools produced by a software manufacturer. A front end generally offers a more user-friendly interface than that of the application running “behind” it. 3. In networking, a client computer or the processing that takes place on it. Compare back end (definition 2).