15.1 use process.argv[0]

There is a hint given for lab 15.1 to use process.argv[0] to refer to the node process instead of 'node'. Can someone please explain why exactly that is. In most of the chapter examples we use process.execPath, why shouldn't we use that or node for this situation? I am assuming process.argv[0] is the first item in an array of arguments, but I would like to know more about it.