为了让同学们更好的理解Socket的底层运作原理，Linux平台下只能使用底层库socket(socket.h)，Windows平台下只能使用Winsock(winsock.h)，请勿使用其它高层封装的Socket库（如Java库，MFC等）。-Linux platform in order to allow students to better understand the underlying principle of operation of the Socket can only use the the underlying repository socket (socket.h for the) Windows platform only use Winsock (winsock.h), do not use other high-level package Socket libraries (such as Java libraries, MFC, etc.).