The OSI Model and TCP/IP Layers

Communication between two computers is a genuinely complicated job. Data has to be turned into signals, addressed to the right destination, routed across many devices, checked for errors, and finally presented to an application in a usable form. Trying to solve all of that with one giant program would be unmanageable. Instead, network engineers break the problem into layers, where each layer handles one part of the job and offers a well-defined service to the layer above it. The two most important layered models are the OSI reference model and the TCP/IP model.

Why layering helps

Layering is an application of abstraction. Each layer hides its internal details and communicates with its neighbors through clear interfaces. This brings several benefits: engineers can design or upgrade one laye