The Open Systems Interconnection model conceptualizes network communications.
The OSI (Open Systems Interconnection) Model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven abstraction layers. It was developed by the International Organization for Standardization (ISO) in 1984.
The seven layers of the OSI model, from bottom to top, are: Physical, Data Link, Network, Transport, Session, Presentation, and Application. Each layer serves a specific function in the process of data transmission between systems.
The Physical layer deals with the physical connection between devices and the transmission of raw bit streams. The Data Link layer provides node-to-node data transfer and handles error correction from the Physical layer.
The Network layer provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks. The Transport layer provides transparent transfer of data between end users.
The Session layer controls the dialogues (connections) between computers. The Presentation layer transforms data into the form that the application accepts. The Application layer is the OSI layer closest to the end user.