final flag (TCP) (FIN)
The final flag is a data field in the control flag field of the TCP header. A set final flag indicates that the sender has terminated the connection and no further data will be transmitted. In the TCP protocol, the connection is terminated in a similar way as the connection is established via the three-way handshake, but when the connection is terminated, the final flag(FIN) is used instead of the synchronization flag ( SYN).