What is the meaning of "Hibernate" in Windows XP/Windows 7?

The computer saves the current state of the system from the computer's RAM to the hard disk, then shuts down. When the computer is restarted, instead of going through the typical boot sequence, the previously saved state is automatically loaded into the RAM. The open windows and running programs from your previous session appear just as they were when the computer entered Hibernate mode. Basically, Hibernate mode acts like Standby mode, except the computer can be completely turned off.

Source : techterms.com