Q1. What is Layered Approach?
Ans. A system can be made modular in many ways. One method is the layered approach, in which the operating system is broken up into number of layers (levels). The bottom layer (layer 0) is the hardware; the highest (layer N) is the user interface.
Figure: Layered Approach
The main advantage of the layered approach is simplicity of construction and debugging. The layers are selected so that each uses functions (operations) and services of only lower-level layers.