params keyword in C#

Stack Overflow illuminates that:

public static int addTwoEach(params int[] args)
{
   return args.Sum() + 2 * args.Length;
}

 
 

...may be called like so:

var foo = addTwoEach(1, 2, 3, 4, 5);

 
 

...and not just like so:

var foo = addTwoEach(new int[] { 1, 2, 3, 4, 5 });

 
 

The second scenario works just fine without the params keyword of course.