The Open Systems Interconnection or OSI model is essentially a reference system that lays out how computers communicate with each other over a network.
It is divided into 7 layers. Each layer has its own domain and receives data from the previous layer, while passing data to the next layer.
The seven layers are:
This is a reference model, meaning that it doesn't actually use it in real life. There is another model which is very similar to the OSI model but it encapsulates the first 3 layers and the last two. This "real life" model is called the TCP/IP Model which is what the internet runs on.
The main post is here.
