Define Three-Tier Architecture?

Define Three-Tier Architecture?

The three-tier architecture has three-layers – the Application-server, the client and the data server.

Application-server-tier: In this tier the business-objects that implement the business rules are stored, and are available to the client-tier. This level forms the central key to solving 2-tier problems. This tier protects the data from direct access by the clients.

Client-tier: The client tier is responsible for the presentation of data, receiving user events and controlling the user interface as the actual business logic has been moved to an application-server.

Data-server-tier: This tier is responsible for data storage. Besides the widespread relational database systems, existing legacy systems databases are often reused here.