What are Async Sockets?

Question

What are Async Sockets? How are they different from normal sockets (Blocking and Non-Blocking)?

Any pointers in that direction or any links to tutorials will be help

Answer 1

Comparison of the following five different models for I/O in UNIX Network Programming: The sockets networking API would be helpful:

Blocking

Nonblocking

I/O multiplexing

Signal-driven I/O

Asynchronous I/O