What is a function module in ABAP?

A function module in ABAP is recognized as a reusable procedure or function that encapsulates a specific piece of functionality or logic. This modularity allows developers to create a piece of code that can be easily invoked from various other programs or function modules. Function modules define a specific interface, which includes input and output parameters, making them versatile for data processing and integration across different areas of an SAP system.

The ability to reuse code through function modules enhances maintainability and reduces redundancy, as multiple programs can call the same function module without duplicating the underlying logic. Additionally, they facilitate a structured approach to programming in ABAP, enabling teams to manage larger codebases more effectively.

While database objects represent structures in the database, generating reports is a process that may utilize function modules but does not define them. User interface elements are part of the presentation layer in SAP and are unrelated to the functional programming aspects provided by function modules.