I am trying to get a rough overview of how Async is implemented (or the idea behind it) before I really dig into its source code.

I have the following questions:

Q1: Is Async event-loop like?

From the API and some docs for Async's usage, I feel it is quite like a event-loop. 

You create Deferred.t and it might be added to a queue and a scheduler behind might be adjusting the order of running for all Deferred.t in the queue. 

Am I correct?

Q2: Deferred.return and Deferred.bind

If I say

It will returns me a Deferred.t, but inside the function return or bind somehow an "event" is implicitly added to the default queue for scheduling, right?

If I am correct above, 

Q3: Is Async depending on -thread? The queue or scheduler needs compiler support? 

I just need to understand the whole picture in a rough way first.

Thanks

Dan