What is three tier architecture?

Three tier architecture typically consists of a client, server and “agent” between them. The agent is responsible for gathering the results and returning a single response to the agent. Such architecture increases performance, reusability and scalability of the application.

The three layers include:-

Presentation layer – This is the topmost layer used to display the information to the user (client). Information is retrieved by communicating with the other layers depending on user events.

Application layer – This is where the logic resides. Processing on the business logic is done thereby controlling applications functionality.

Data layer - This is where the data resides. Typically consists of the database servers. The data here is independent of the business logic.