There are four types of drivers defined by JDBC as follows:
Type 1: JDBC/ODBC—These require an ODBC (Open Database Connectivity) driver for the database to be installed. This type of driver works by translating the submitted queries into equivalent ODBC queries and forwards them via native API calls directly to the ODBC driver. It provides no host redirection capability.
Type2: Native API (partly-Java driver)—This type of driver uses a vendor-specific driver or database API to interact with the database. An example of such an API is Oracle OCI (Oracle Call Interface). It also provides no host redirection.
Type 3: Open Protocol-Net—This is not vendor specific and works by forwarding database requests to a remote database source using a net server component. How the net server component accesses the database is transparent to the client. The client driver communicates with the net server using a database-independent protocol and the net server translates this protocol into database calls. This type of driver can access any database.
Type 4: Proprietary Protocol-Net(pure Java driver)—This has a same configuration as a type 3 driver but uses a wire protocol specific to a particular vendor and hence can access only that vendor's database. Again this is all transparent to the client.
Note: Type 4 JDBC driver is most preferred kind of approach in JDBC.