what is the difference between hibernate & DAO(Data Access Object)?

Answer 1

What's the difference between an apple and a house?
Hybernate is a method for a computer to shut down, but retain it's previous state, including applications being open, and the data being used. It's a snapshot of RAM and registers, stored to disk so that when the computer restarts, you're right where you were.

DAO is a method of access to data used by programs.