Layers are an abstract form of model representing the transportation of requests.
An example of this is the OSI model and TCP/IP.
Each layer is completely independent and has one sole responsibility, i.e., the ‘Transport’ layer handles only the transportation of the request.
Each layer has specialised technology and/or software.
Advantages
- Decomposition - reducing a complex problem into smaller problems
- Devices can be manufactured to operate at a particular layer
- Products from different vendors will function together
- Easier to debug
- You can identify where problems occur and hone in on that specific layer