coroutines are used to make your code appear to execute without a need for a callback, and in order to create a coroutine one must wrap the function doing the awaiting in a generator.

now, I am assuming (perhaps incorrectly) that the async keyoword marks the function for wrapping, and await lets you know where the yields should go. or something like that :)

of course, now thats its all native, I have no idea any more