subroutine

A named or otherwise accessible piece of program that can be invoked from elsewhere in the program in order to accomplish some sub-goal of the program. A subroutine is often parameterized to accomplish different but related things depending on its input arguments. If the subroutine returns a meaningful "value", it is also called a "function".

A set of computer instructions (or pieces of code) that run within a program (or are called within a program) to carry out a predefined function or computation. Note: "Open" subroutines are integrated into the main program. "Closed" subroutines are arranged so that program control is shifted to them for execution of their task(s) and then returned to the main program.