As far as I know, using AJAX is already inappropriate (unless in those cases when you do not need to constantly monitor the statistics of something and the information on time is not particularly important)
What to do when we need to implement an application that will be implemented on sockets in different parts, the same Internet resource where it is important to see if there is a person on the network or not, whether he writes to you in chat or not, whether he left a record on the wall or no (yes, roughly speaking is an example of VC)
So what you need to know about sockets, so that you can safely write network applications of any complexity? What literature is required for this?
PS Comrades who voted to close the question, what exactly does not suit you? I wrote a specific question! What is wrong?
Самоучитель игры на WINSOCKbut from it there is little knowledge of the fact that it is not so deep, so superficial - MaximPro