Answer Description
The OSI model from 1-7: Physical, Data Link, Network, Transport, Session, Presentation, Application
Wikipedia
The Open Systems Interconnection model (OSI model) is a conceptual model that characterises and standardises the communication functions of a telecommunication or computing system without regard to its underlying internal structure and technology Its goal is the interoperability of diverse communication systems with standard communication protocols The model partitions a communication system into abstraction layers A layer serves the layer above it and is served by the layer below it For example, a layer that provides error-free communications across a network provides the path needed by applications above it, while it calls the next lower layer to send and receive packets that constitute the contents of that path
OSI_model - Wikipedia, the free encyclopedia