Can you explain the concept of a layer in software architecture?

A layer in software architecture is a logically separated level responsible for a specific set of functions or tasks within an application. Layer separation helps structure the code, improve its maintainability, and scalability.

For example, common layers include:

• Presentation (UI) — responsible for displaying data and user interaction.
• Business Logic — contains rules and data processing.
• Data Access — responsible for working with databases or external services.

In iOS applications, layers can be implemented through View (UIViewController), Model, and Controller, corresponding to the MVC pattern. Each layer interacts with adjacent layers but does not depend on the implementation details of other layers, which simplifies development and testing of the application.