OSI model has a separate Presentation layer and Session layer. Network layer of OSI model provides both connection oriented and connectionless service.
It is a robust and flexible model. Whereas, OSI is a conceptual model.
Hosts use a discovery protocol to obtain the identification of gateways and other hosts attached to the same network subnetwork. Protocols are hidden in OSI model and are easily replaced as the technology changes.
It translates the network logical address into physical MAC address so that the two systems residing in the different networks could also communicate efficiently.
It performs tasks such as translation, encryption and compression where the actual information existing in the form of character strings, numbers, symbols is encoded into bit streams, converted into another form and compressed. Since these two layers deal with functions that are so inherently specific to each individual networking technology, the layering principle of grouping them together related functions is largely irrelevant.
The transport layer of the OSI model checks source-to-destination reliability. Over the years it has handled most challenges by growing to meet the needs.