Abstract: The system is based on B / S (browser / server) applications， including TCP and UDP communication programming， network programming using sockets to achieve inter-process communication， so as to achieve LAN communication， including friends such as management and private chat Including friends such as management and private chat The system is mainly used in schools， companies and other communications within a small unit within the LAN in order to solve the communication of information between different users within the same LAN， but also better able to achieve resource sharing between
