Define the layering pattern

What will be an ideal response?

Layering is one of the most common patterns used in software architecture. A layer is a collection of components that provide similar services or are highly dependent on each other for performing their services. The basic idea is simple: to manage a complex architecture, aggregate components that perform the same kind of services, plus components that support them, into distinct layers. In such a structure, horizontal layers embody a hierarchy: the lower layer supports the upper layer, and the upper layer relies on the services of the lower one.
Layers can be both horizontal and vertical. Vertical layers run across all horizontal layers, control them, sometimes use their services and, most importantly, connect the layers together.
The relationship between conceptual, logical, and physical layers is not necessarily one-to-one. For a number of reasons, a conceptual layer might not become a logical or a physical layer. (A physical layer on a separate server is called a tier; hence the terms "two-tier," "three tier," and "n-tier".) Nevertheless, conceptual layering is always useful, regardless of whether it is implemented as physical layers or not. At the very least, it is an incentive to clearly define what kind of responsibilities your classes must have.