The JDBC, when used to connect a server or servlet component with a DBMS, may be configured as shown below.
Controller
The controller is a component that includes function to determine the action to be performed. Thus, for a database application, it might determined whether the user or client application intends to add, search, update, or delete. It would then call the appropriate method in the Mapper object.
Mapper
The Mapper maps between Java objects and DBMS "objects." More specifically, it maps between Java objects and SQL statements "going in" and "coming out" from specialized Java objects that directly mirror DBMS tables and meta-information and Java databeans or other more general Java objects.
Driver
Drivers are utility programs written by vendors that map between Java programs and some DBMS.
DBMS
Vendor-supplied systems that provide general support for multiple database applications.
DB
The data maintained by a DBMS for a particular database application.