A C# Server Socket Program running on a computer has a socket that bound to a Port Number on the same computer and listening to the client's incoming requests.

http://www.c-sharpcorner.com/UploadFile/ajyadav123/applied-C-Sharp-net-socket-programming/

http://csharp.net-informations.com/communications/csharp-socket-programming.htm

Socket is a Port in System. We can Send and receive data using Socket using different protocols.Tcp, UdP etc.

Socket programming in c# is get communicate from front end to back end or client side to server side through some protocols

socket programming in .NET Framework using C#. Secondly, we will create a small application consisting of a server and a client, which will communicate using TCP and UDP protocols.