A sequence of instructions that is used when a program is started and is central to its structure, being able to invoke subprograms or subroutines as required and being itself executed by the operating system.
Origin
1950s.
Definition of main program in US English:
main program
noun
Computing
A sequence of instructions that is used when a program is started and is central to its structure, being able to invoke subprograms or subroutines as required and being itself executed by the operating system.