What is socket programming?

Question

Hi guys,
2 days ago one of my friend told me he just started learning socket programming.
i don't have any idea what he talking about.
so anyone here who can help me understand what socket programming is?
what is the purpose of using it?
what's it application?

Answer 1

A socket is one endpoint of a two-way communication link between two programs running on the network. A socket is bound to a port number so that the TCP layer can identify the application that data is destined to be sent to. An endpoint is a combination of an IP address and a port number.
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Answer 2

can u please suggest a book for learning socket programming?

Answer 3

What languange?

Answer 4

Java program that implements Socket Programming? Anyone to help