Briefly describe the four JDBC driver types that Sun defines?

Type1 drivers provide a bridge between Java and ODBC. Types2-4 drivers are written entirely in Java, but differ as to how they connect to the DBMS. Type2 drivers rely on the DBMS product for intermachine communication, if any. Type3 drivers translate JDBC calls into a DBMS-independent network protocol. Type4 drivers translate JDBC calls into a DBMS-dependent network protocol.