Layered Architecture (N-Tier)
- Computer Science Department
Layered architecture, also known as n-tier architecture, is a common architectural style in software development where the application is divided into different layers or tiers, each having a specific responsibility and functionality. The idea is to reduce dependencies between the components of the application and promote separation of concerns.
The number of layers can vary based on the application's requirements, but a traditional four-layered architecture often includes:
Presentation Layer (User Interface): This is the topmost layer that interacts with the user directly. It's responsible for displaying information to the user and interpreting user commands. It generally includes the user interface and UI process components.
Application Layer (Service Layer): This layer is used to define the business logic and rules of the application. It provides a bridge between the presentation layer and the business layer, and controls the application’s functionality by performing detailed processing and validations.
Business Logic Layer (Domain Layer): This layer is responsible for implementing the core business logic of the system, i.e., the rules that govern the data's processing. It includes entities, services, and interfaces that encapsulate the significant business behaviors and state.
Data Access Layer (Persistence Layer): This layer interacts with the database or any other storage system. Its responsibility is to retrieve, update, and save data. It may communicate directly with the database or use an Object-Relational Mapping (ORM) tool.
These layers communicate with each other in a strict hierarchy, meaning the upper layer can communicate with the layer just below it, and the lower layer can communicate with the layer just above it.
One of the main benefits of layered architecture is the separation of concerns, which means that each layer can be developed, updated, and tested independently of the other layers. This approach also makes the application more maintainable and adaptable to changes.
However, it's important to note that while layered architecture can offer many benefits, it may not be suitable for all types of applications, especially those with complex workflows or those requiring high performance. Each situation requires careful consideration when choosing an architectural pattern.