The parameter/argument is input highlighted below in the two examples:
// ES6 - Version
inputs.forEach(input => input.addEventListener('change', handleUpdate));
//ES5 - Version
return input.addEventListener('Change', handleUpdate);
If I change the name of these two for example from input to abc it still works, I assume it is not referencing the input tags in the HTML since I can change the name and it still works, I thought it might be the event object but Im a bit of a newbie so I cant understand why it would be the event object?
And if it is referencing the input I don't understand what tells it to pull the input in?
Here is a JS Fiddle example: