Layered architecture is a design paradigm in software engineering that organizes a system into distinct layers, each with specific responsibilities and functionalities. This approach promotes separation of concerns, making systems more modular, maintainable, and scalable.

Key Characteristics:

- Separation of Concerns: Each layer addresses a specific aspect of the system's functionality, reducing interdependencies and simplifying maintenance.

- Modularity: Layers function as independent modules, allowing for isolated development, testing, and updates.

- Abstraction: Higher layers interact with lower layers through well-defined interfaces, abstracting underlying complexities.

Common Layers in Software Systems:

1. Presentation Layer: Manages user interactions, handling inputs and displaying outputs.

2. Application Layer: Contains business logic and rules governing data processing and decision-making.

3. Data Access Layer: Facilitates communication between the application layer and data storage, managing data retrieval and manipulation.

4. Data Storage Layer: Responsible for storing and retrieving data, typically involving databases or file systems.

Advantages:

- Maintainability: Isolated layers enable easier identification and resolution of issues.

- Scalability: Individual layers can be scaled independently based on system demands.

- Reusability: Layers can be reused across different projects or systems with similar requirements.

Disadvantages:

- Performance Overhead: Multiple layers can introduce latency due to additional processing and communication.

- Complexity: Designing and managing numerous layers may increase system complexity.

- Layered architecture is prevalent in various domains, including enterprise applications, network protocols, and operating systems, due to its structured approach to system design.