What are 3 of the same things as a layer?

Three things that can be described as layers are: a cake, which consists of multiple tiers of cake and frosting; sedimentary rock, which forms through the accumulation of mineral layers over time; and a software application, which often has multiple layers of architecture, such as the presentation layer, business logic layer, and data access layer. Each of these examples showcases how layers can build complexity and depth in different contexts.