A two-tier architecture is a software architecture in which a presentation layer or interface runs on a client, and a data layer or data structure gets stored on a server. Separating these two components into different locations represents a two-tier architecture, as opposed to a single-tier architecture.

To talk about the advantages and disadvantages, consider the following points.

The advantages of Two-Tier systems are as follows:

• The system performance is higher because business logic and database are physically close.
• Since processing is shared between the client and server; more users could interact with system.
• By having simple structure, it is easy to setup and maintain entire system smoothly.

The disadvantages of Two-Tier systems are as follows:

• Performance deteriorates if number of users increases.
• There is restricted flexibility and choice of DBMS since data language used in server is proprietary to each vendor.