The TCP/IP model

The TCP/IP model is a reference models of networking which was invented by the Department of Defense in the 1960s. Its comprised of 4 layers.

Level 4 - Application Layer - Contains high-level protocols like HTTP.
Level 3 - Transport Layer - Responsible for ensuring data is not lost when it is sent .
Level 2 - Network Layer (Internet Layer) - Responsible for routing packets over the entire network.
Level 1 - Network Access Layer (Link Layer) - Deals with how bits are sent on a wire or transmitted through the air as waves, as well as the detection and correction of errors.

In this tutorial, we will look at each layer of the TCP/IP model.

ARPAnet

The Open Systems Interconnection model (OSI model) is a reference model from the International Organization for Standardization (ISO) that provides a common basis for the coordination of standards development for the purpose of systems interconnection. [2] In the OSI reference model, the communications between systems are split into seven different abstraction layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.[3]

Number 3 The OSI Model

The Open Systems Interconnection model (OSI model) is a reference model from the International Organization for Standardization (ISO) that provides a common basis for the coordination of standards development for the purpose of systems interconnection. [2] In the OSI reference model, the communications between systems are split into seven different abstraction layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.[3]