Keeping in mind that TCP connections are full duplex, we can view them as being two independent pipes of communication between the two host computers. When an application program has no more data to send, it informs the TCP service. The TCP closes its half of the connection by sending the rest of the data that may be buffered and then sends a segment with the FIN flag set. The receiving TCP acknowledges the receipt of the FIN segment, and informs its own application that there will be no more data received. The TCP that is still open may continue to send data onto the original TCP until it terminates the connection itself, the application may still have data to send even though the other TCP has finished. When both connections are closed, the connection is deleted.