JDBC supports 2 kinds of processing models to access the DB.
* Two-tier Architecture : Here Java programs explicitly connect with DB. We don’t need any mediator like applications server to connect with DB except the JDBC driver. It is also known as a client-server architecture.
* Three-tier Architecture : It is totally inverse of two-tier architecture. There will be no explicit communication between the JDBC driver or Java program and Database. An application server is used as a mediator between them. Java program will send the request to an application server, and the server will send it and receive the response to/ from DB.
