The first program unit that starts executing when a program is run. The first statement of a main program usually is the PROGRAM statement.

a series of statements that are compiled as a unit

(n.) a program unit that is not a module, subprogram or block data program unit.

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.