What do you call a value that is passed to a subprogram?

The term that refers to a value passed to a subprogram is known as an "Argument." In programming, an argument is the actual value that is supplied to a function or method when it is called. This value can be used within the subprogram to perform operations.

On the other hand, a parameter is a variable in the subprogram that receives the value of the argument. While parameters define what type of arguments a function can accept, the actual values given when calling the function are called arguments.

Variables are broader in scope and represent storage locations in memory that can hold data values, while a return value is what a subprogram outputs after execution. Thus, "Argument" correctly identifies the value passed to a subprogram, highlighting its role in the function's operation.