Which term is used to describe a process or step within a program?

The term that best describes a process or step within a program is "function." In programming, a function is a specific block of code designed to perform a particular task or operation. It encapsulates a series of instructions that can be executed when the function is called. This concept allows for modular programming, where complex tasks can be broken down into simpler, reusable components, thus improving code organization and readability.

While "operation" may refer to actions performed by functions, it is a more general term and does not specifically denote the encapsulated set of instructions characteristic of a function. "Iteration" refers to the process of repeating a set of instructions or a block of code, typically using loops, rather than defining a specific step in a program. The term "process" itself is broader and can describe various activities within computing, but lacks the specificity of a function, which is explicitly recognized as a self-contained unit of code within a program.