Sorry, but it is blindingly obvious that you have no idea what is meant by asynchronous IO.

Specifically, it is not a select loop. To correct your analogy, it is definitively not the following:

Imagine employing an intern to sit in the reception of your office block, and have him or her verbally relay each part of each telephone call coming in or out of the build. Ie. there is no direct connection between the outside lines and the internal extensions.

When Mrs. Brown calls to speak to accounts. The receptionist listens to her question and then calls Accounts and repeats it. Then listens to Accounts response and repeats it on the outside line to Mrs. Brown.

At the same time, s/he, the receptionist, is doing the same thing between: HMRC and the Audit Department; and between the Chairman and his wife; and between Goods-in and the Post Office; the head of HR and a sacked employee; the post guy and his boyfriend; the cook and a wholesaler; and the Chairman and his girlfriend; ...

Needless to say, "polishing nails" doesn't get a look in.

That is a fairly accurate analogy of a select loop. All state visible from the one point in the program. No way to prioritise one event over another; or one event type over another, much less one particular conversation over another. All your eggs in one basket. Always fighting fires.

No, Asynchronous IO, also known as Overlapped IO, is a quite, quite different beast.

I suggest you look it up -- you know, do a little research, ensure that you know what it is you're pontificating about -- before you torture any more incorrect analogies to death.