Hibernate is a power management feature in computers that allows them to save the current state of the system to the hard disk and then turn off the computer. When the computer is turned back on, it can quickly restore the system to its previous state, allowing users to pick up where they left off without having to wait for the computer to boot up. Hibernate is particularly useful for laptop users, as it allows them to conserve battery life while still being able to resume work quickly. Hibernate is available in most modern operating systems, including Windows, macOS, and Linux.