Difference between Argument and Parameter

Programmers use the terms argument and parameter interchangeably. When someone says argument or parameter, they mean the same thing. However, there is a difference.

Parameter Vs. Argument

Parameters are named variables declared in the function definition.

Arguments are variables or values passed to the function when calling it.

This definition is universal, irrespective of programming language. Let us consider the following Python function:

def multiply(x, y):
  return x * y;

multiply(10, 15);

In the above example, the function multiple() expects two parameters: x and y. Next, when the function multiply() is called, two arguments are passed to the function: 10 and 15. Therefore, arguments are runtime values that fill the function parameters.