http://java.sun.com/blueprints/patterns/DAO.html JDBC is a API provided by SUN to access relational database. DAO is defined by the developer. Suppose I want to access Employee info which may be stored in some flat files,RELATIONAL database or some OODMS. I define an interface with methods that will allow me retrieve, update or delete functionlities. My business logic will talk to the interface only.
I could then implement the interface for say, Oracle Database and have SQL code inside the implemented methods.
In case I need to access employee info stored in some other datastore I will be creating another implementation class without touching the business logic.
[ August 14, 2003: Message edited by: Pradeep Bhat ]