That does answer my question, but I don't really understand why the distinction is made. To the caller, a function that spends time waiting and a function that spends the same time calculating both look the same, don't they?
The difference is that the runtime can schedule something else if the blocking is async. It looks the same as sync blocking to the caller, but not the scheduler. The point of async is you can write code that looks synchronous but is actually participating in cooperative multitasking.
