Make sure to turn your firewall OFF in case you want to set up a server on one host and client on the other host.
Suppose the above server program is running. It takes 10 secs for the server to completely process the request.\
Suppose Client A requests the server at t = 0s.\
At t=5s Client B requests the server. The Client A and Client B are now waiting to receive a response.\
Then at t=10s server will send its response to Client A and at t=11s it will start processing request of Client B.\
The Client B will keep on waiting until it receives the response from server which it will receive at t=20s\