The OSI (Open Systems Interconnection) Model was developed in the 1970s and 1980s, and it is a conceptual model that breaks networking into seven separate layers. Each layer refers to a set of functions that are responsible for specific tasks. The layers start from physical signals all the way up to the web applications we interact with. Each layer generally only interacts with the layer below it and provides useful tools or information to the layer above it.
This is a conceptual model, meaning it is neutral to specific implementations or standards. We will talk about the TCP/IP Model, which maps to specific implementations, later in this lesson. OSI is used to help us categorize network processes so we can communicate about them during troubleshooting and while improving security.
We’ll talk about the seven layers over the next few exercises.