What describes the N-tier application architecture model?

The N-tier application architecture model is characterized by its separation of concerns, where different functionalities of an application are distributed across multiple layers or tiers. This model typically includes multiple databases, front-end servers, and application servers, which communicate over a network. By separating these components, the architecture allows for greater scalability, flexibility, and manageability of the application.

In an N-tier architecture, the front-end server handles user interface interactions, the application servers manage the business logic, and the databases are responsible for data storage and management. This distribution allows for improved performance because different tiers can be optimized independently, and it also enables easier updates and maintenance as changes can often be made in one tier without affecting the others. Therefore, the presence of multiple databases, front-end servers, and application servers is a defining feature of the N-tier architecture, supporting the complexity and demands of modern applications.