Can you explain the concept of layered architecture and its main components?

Layered architecture is an approach to software design where the system is divided into several independent layers, each responsible for its own area of concern. The main idea is to separate code by functional areas to improve maintainability, testability, and scalability.

Main components of layered architecture:

1. Presentation Layer — responsible for user interaction, input processing, and data display.
2. Business Logic Layer — contains application rules and logic, data processing, and decision-making.
3. Data Access Layer — responsible for interacting with the database or other data storage.
4. Model — objects and data structures used within the application.

In Go, this might look like: separate packages for handling HTTP requests (presentation), services with business logic, repositories for database interaction, and data models.