AdvantagesThree-Tier Architecture

•Changes in the user interface or the application logic are largely independent from one another, allowing the application to evolve easily to meet the new requirements
•Network bottlenecks are minimised because the application layer does not transmit extra data to the client; instead it transmits only what is needed to handle a task.
•When business logic changes are required, only the server has to be updated, in two-tier architecture, each client must be updated when logic changes.
•The client is insulated from database and network operations, the client can access data easily without having to know where data is or how many servers are on the system
•Database connection can be pooled and thus shared by several users, which reduces the cost of per-user licensing
•The application layer can be written in standard third- or fourth-generation languages, such as Java or C, with which the organisation's in-house programmers are experienced.
•The organisation has database independence because the data layer is written using standard SQL, which is platform independent