Transmission Control Protocol (TCP) is one of the main protocols of the Internet Protocol Suite. It enables two hosts to establish a connection and exchange data. TCP guarantees delivery of data and also guarantees that packets will be delivered in the same order in which they were sent.
It is a reliable, ordered, and error-checked delivery of a stream of bytes from one host to another on a network. Most of the Internet's high-level protocols use TCP, including the World Wide Web (HTTP), Email (SMTP, IMAP, and POP), and file transfer (FTP).
TCP's reliability makes it suitable for use in server systems and other network-based software applications.