subprogram

A subprogram, also known as a procedure, subroutine, or function, is a semi-independent portion of a computer program. These are essential building blocks in computer science, allowing programmers to break down complex tasks into smaller, more manageable parts.12

Think of a subprogram like a recipe that can be used within other recipes. It takes inputs, performs a specific set of operations, and produces an output or result. Commonly used subprograms are often stored in libraries provided with programming languages.2

Subprograms can also call other subprograms, creating a hierarchy of operations. In some cases, a subprogram can even call itself, a concept known as recursion, which can be a powerful way to solve problems that can be broken down into smaller, self-similar instances. This modular approach makes programs easier to write, understand, and maintain.2