What is "gosub"

GOSUB is a command in many versions of the BASIC computer programming language. A GOSUB statement jumps to a line elsewhere in the program. That line and the following lines up to a RETURN are used as a simple kind of a subroutine without (sometimes with) parameters or local variables.

The GOSUB command may be used to emulate functions in a BASIC dialect that does not support functions in its syntax. GOSUB is convenient for performing the same function several times in a BASIC program without duplicating the code.