Each entity interacted directly only with the layer immediately beneath it, and provided facilities for use by the layer above it.
Protocols enable an entity in one host to interact with a corresponding entity at the same layer in another host.
Its goal is the interoperability of diverse communication systems with standard protocols.
The model partitions a communication system into abstraction layers.
Although the OSI model is often still referred to, the Internet's TCP/IP protocol suite is used in lieu of the OSI protocols.