What happens is that `urlfetch.make_fetch_call()` makes an asynchronous request. You can then go and do other things until you need to get the result. At the time you need the result, you do `rpc.get_result()` and it either immediately has the result because the async rpc already finished while you were doing other things, or it waits until the rpc finishes so you can have the result. The benefit is everything you do between the two is 'free' because you weren't blocking on the request.