The transmission control protocol
A TCP is a connection-oriented protocol used by various other application-layer protocols to ensure data delivery without any loss of packets during transition. On the basis of sequence numbers and acknowledgement numbers, a TCP ensures fail-proof delivery of packets between the hosts that intend to communicate. A TCP is supposed to provide an end-to-end, reliable form of communication, which should be robust at all times. It sits in between the network layer and the application layer and uses the IP datagram to transfer data packets between the sender and receiver. Because of this approach, the TCP and IP are used by various application layer protocols for their reliable delivery.
A TCP is like a two-way communication process where not only the sender is involved in the communication, but even the receiver actively works to make it a successful connection. You can imagine it to be like a landline connection, where you dial a number; if the number you dialed...