The first program in an application. This program receives control when the application is invoked.
A part of a program which calls subprograms but cannot be called by them.
The first program unit to receive control when a program is run.
In Fortran, a program unit, required for running, that can call other program units but cannot be called by them.
(IEEE) A software component that is called by the operating system of a computer and that usually calls other software components. See: routine, subprogram.