In this tutorial you will learn: SAP- ABAP Macro, Include Programs, Subroutines, Function Modules, Function Groups (SE80)

SAP ABAP - Subroutines - A subroutine is a reusable section of code. It is a modularization unit within the program where a function is encapsulated in the form of source code.

Subroutines are the procedures which are derived from the ABAP program. It can be called from any program within the same program. Subroutines frequently use sets of codes and algorithms internally. You can call the subroutines from the external programs