The database management system design depends on its architecture. A large number of computers, database servers, web servers, and other components which are connected with networks are handled by a basic client/server architecture. It consists of a large number of computers and a workstation connected with a network. The architecture of the DBMS depends on how users are connected to the database to get their requests fulfilled.
Databases are of multiple, and they can be seen in a multi-tier or single tier way. If you see Databases logically are either of two-tier architecture or three-tier architecture.
Single tier architecture:
In this architecture, the user is directly connected to the database management system. It means that the user directly sits on the database and use it as per requirement. Any changes done by the user to the database are direct, and it does not provide any handy tool for the end users. Developers use single tier architecture for the development of the application. Here the programmers can directly communicate with the database to reduce the communication time.
Two-tier architecture:
The two-tier architecture used in the database management system is the same as the basic client-server which we have seen. In this architecture, the application at the end of the client can directly communicate with the database in the server. In this interaction, APIs are used which are commonly ODBC or JDBC. The application programs and the user interface run on the side of the client. The server side is responsible for transaction management and query processing.
Three tier architecture:
In the three-tier architecture, there is an additional layer between the client and the server. Thus, the client and the server cannot directly communicate with each other. The applications on the client side and server side interact, which then communicates with the database. The user has no idea about the database beyond its application, and similar is the case where the database does not know the user beyond the server application.