Who implements the methods of JDBC (java.sql.*) interfaces

Question :Who implements the methods of JDBC (java.sql.*) interfaces?
e.g.resultSet.next() is a method in ResultSet interface and Sun doesn't
provide any
implementation for this method. Who actually provides the
implementation. (JDBC)
Answer :Its the JDBC Driver vendor. Java provides the specifications for the
interfaces
and its the vendor who has to implement those methods.