How does the printList function know it should receive the playList array as an argument?

var playList = [
  'I Did It My Way',
  'Respect',
  'Imagine',
  'Born to Run',
  'Louie Louie',
  'Maybellene'
];

//My new array with my favorite colors
var myFavoriteColors = [
'Green',
'Blue',
'Orange'
];

function print(message) {
  document.write(message);
}

function printList( list ) {
  var listHTML = '<ol>';
  for ( var i = 0; i < list.length; i += 1) {
    listHTML += '<li>' + list[i] + '</li>';
  }
  listHTML += '</ol>';
  print(listHTML);
}

printList(playList);
//I just added a new call to printList and passed in my array I created
//that has my favorite colors
printList(myFavoriteColors);