Transmission Control Protocol/Internet Protocol (TCP/IP) is the communication language of the Internet that lets the hosts to connect to the Internet.
The upper layer TCP assembles the message into smaller packets which are sent over the Internet by the source computer and received by the TCP layer of the destination computer. The sender and the receiver “understand’ the language of their respective layers. The lower layer which is called the IP (Internet protocol) layer manages the address of each packet so that it is dispatched to the right destination.