What are the main differences between OSI and TCP/IP reference model?

What are the main differences between OSI and TCP/IP reference model?

we will be focusing only on the key differences between the two reference models. Three concepts are central to OSI model: services , interfaces, and protocols. OSI model makes their clear distinction between these three concepts.

The TCP/IP model did not originally clearly distinguish between services, interfaces and protocol. For example, the only real services offered by the internet layer are SEND IP packet and RECEIVE IP packet.

The OSI reference model was devised before the protocols were invented. This ordering means that model was not biased towards one particular set of protocols, which made it quite general. With TCP/IP reverse was true: the protocol came first and the model was really just a description of the existing protocols. So problem was model did not fit for any other protocol stack.

Another difference is in the area of connectionless versus connection-oriented communication. The OSI model support both connectionless and connection oriented communication in network layer, but only connection oriented in the transport layer. The TCP/IP model has only connectionless mode in network layer but supports both the mode in transport layer.