JDBC driver and datasource

JDBC-Implementation of Connection,Resultset,Statement

In JDBC We use Connection,Resultset,Statement..etc.
All these are interfaces, but we are using it..
My Question is:
1.Where is the implementation of these interfaces?
2. We will load the JDBC driver in the first step.. Instead can we put the driver class in class path? Why loading class using Class.forName()
3.What is the difference between using JDBC driver and datasource?

Thanks in advance.

JDBC driver is used to communicate the data to and fro. DataSource is an entry point in the database where we will enter into database and schemas.

Java DataBase Connectivity API provides only interfaces so that using JDBC in your application will be independent of different types of Databases like Oracle, MySQL etc. And the database vendor like Oracle etc. provides the implementation of these interfaces specific to their product.

When you are running ur application you will provide some .jar or .zip files namely ojdbc14.jar etc. in your classpath. These jar/zip s are nothing but the classes(Vendor specific) which provides the implementation JDBC API.

If u can observe, when u want to create a statement object, u will call createStatement() method on Connection object. These methods are factory methods which contains the implementation of Statement interface.