The OSI Layer Model is composed to seven layers, each representing an abstract concept which is used in network communication. Each layer is served by the layer below it. Through traversing the OSI model, data is divided into segments, then packets then frames and then finally into individual bits. The data travels from the top of the model, to the bottom and then back to the top at the other end of the connection.
It is very important to be familiar with the OSI Model. Both for certifications, such as Netowk+ or CCNA, and for the real world. Network engineers will ofter say there they are seeing a 'Layer 2 problem' or they see an issue on the 'Network Layer'. You will look awfully silly if you do not know what they mean when they make such references. You should know and understand the different layers, along with which protocols live on which layer.
Place the seven layers of the OSI Model into their correct order by clicking on a layer's name and then clicking on an empty box.
Move to:Layer 7
The TCP/IP Model or Internet protocol suite servers the same function as the OSI Layer model, but is divided into four logical layers. Each of these four layers corresponds to one or more OSI Model layers. As above, practice memorizing the order of this model by ordering the layers from top to bottom.