"Transmission Control Protocol, or TCP, is part of the Internet protocol suite. It is often referred to as TCP/IP. TCP/IP controls the transmission of data across the network, ensuring that the right information is exchanged between the network nodes. Common TCP connection states include:
LISTEN, when the server is listening for traffic, SYNC-SENT, after a request is sent and the servicer is waiting for a response, SYN-RECEIVED, when the servicer is waiting for a response to an ACK signal, and ESTABLISHED, which indicates that a three-way TCP connection has finished."