when to say parameter or argument in javascript code example

Example 1: argument vs parameter javascript

var foo = function( a, b, c ) {}; // a, b, and c are the parameters

foo( 1, 2, 3 ); // 1, 2, and 3 are the arguments

Example 2: javascript function variable arguments

function foo() {
  for (var i = 0; i < arguments.length; i++) {
    console.log(arguments[i]);
  }
}

foo(1,2,3);
//1
//2
//3