TCP/IP:
HTTP is an application layer protocol. HTTP doesn’t worry about the nitty-gritty details of network communication; instead, it leaves the details of networking to TCP/IP, the popular reliable Internet transport protocol.
TCP provides:
• Error-free data transportation
• In-order delivery (data will always arrive in the order in which it was sent)
• Unsegmented data stream (can dribble out data in any size at any time
The above image shows that the HTTP messages that might be sent as part of a simple transaction. The browser requests the resource http://www.joes-hardware.com/tools.html.
The Internet is based on TCP/IP, a popular layered set of packet-switched network protocols spoken by computers and network devices worldwide. TCP/IP hides the peculiarities and foibles of individual networks and hardware, letting computers and networks of any type talk together reliably.
Once a TCP connection is established, messages are exchanged between the client and server computers will never be lost, damaged, or received out of order.
In networking terms, the HTTP protocol is layered over TCP. HTTP uses TCP to transport its message data. Likewise, TCP is layered over IP which can be seen in the below image.
The above image is HTTP network protocol stack.