sequence of instructions that can be called from other points in a computer program

In computer programming, a subroutine is a code that is comprised of more codes — just like everything in programming — its purpose is the same: execute an instruction/command. Because subroutines are shorter, they can be typed faster and therefore be used more by programmers, hence saving time by being able to code faster.

Subroutines are commonly paired with parameter, a type of variable.