Windows Sockets Classes
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Windows Sockets provide a network protocol-independent way to communicate between two computers. These sockets can be synchronous (your program waits until the communication is done) or asynchronous (your program continues running while the communication is going on).
CAsyncSocket
Encapsulates the Windows Sockets API in a thin wrapper.
CSocket
Higher level abstraction derived from CAsyncSocket. It operates synchronously.
CSocketFile
Provides a CFile interface to a Windows Socket.