The JDBC technology (Java DataBase Connectivity) is an API provided with Java (since version 1.1), allowing you to connect to databases. That is to say, JDBC is a set of classes for developing applications that connect to databases servers (DBMS).
The JDBC API has been developed to allow a program to connect to any database using the same syntax (the JDBC API is independent of the DBMS).
In addition, JDBC enjoys the benefits of Java, including the portability of the code.
Accessing databases with JDBC
In a client/server system, access to databases with JDBC can be either represented using a two-layers or three-layers model.
For the two-layer model, the Java application is closely linked with a database. To this end, it must obviously have for the relevant database, the appropriate JDBC driver. SQL statements are sent directly to the database and the latter will directly return the results. The database can be run on the local machine (the one running the Java application) or on any other computer on the network (Intranet or Internet).
In the 3-layer model, a third layer (the application server) is interposed between the Java application and the database. This model has the advantage of integrating an access control feature.