We know that there are two models OSI and TCP model. But TCP/IP protocol is different from TCP model as this protocol used in both OSI as well as TCP model. So why the two are named the same is confusing. My question is: what's the difference between TCP/IP protocol and TCP model?
TCP/IP is a protocol stack which contains different protocols required for the data transfer from sender to receiver.
TCP - Layer 4 protocol which ensures reliability and is connection oriented.
TCP/IP is also a layered protocol but does not use all of the OSI layers, though the layers are equivalent in operation and function (Fig. 2). The network access layer is equivalent to OSI layers 1 and 2. The Internet Protocol layer is comparable to layer 3 in the OSI model. The host-to-host layer is equivalent to OSI layer 4. These are the TCP and UDP (user datagram protocol) functions. Finally, the application layer is similar to OSI layers 5, 6, and 7 combined.
The TCP layer packages the data into packets. A header that’s added to the data includes source and destination addresses, a sequence number, an acknowledgment number, a check sum for error detection and correction, and some other information. The header is 20 octets (octet = 8 bits) grouped in 32-bit increments.