What term refers to a set of program instructions?

The term that refers to a set of program instructions is 'Code.' In programming, code consists of written instructions that tell a computer how to perform specific tasks. This can include a variety of elements like functions, variables, and control structures that work together to create software applications, scripts, or any other form of computer programs.

While syntax refers to the rules that govern the structure of a programming language, and an algorithm is a step-by-step procedure or formula for solving a problem, code is the actual implementation of those algorithms in a specific programming language. A script, on the other hand, is a type of code that is often interpreted rather than compiled but is not a general term for all program instructions. Thus, 'Code' is the most accurate answer when describing a set of program instructions.