Definition - What does Hibernate Mode mean?
Hibernate mode is a power management mode that powers down the computer while maintaining its previous state. In this mode, the current state of the system is saved from the random access memory (RAM) to the hard drive before shutting the system down. When the user turns the system back on, the computer resumes its pre-hibernation state.
Techopedia explains Hibernate Mode
This mode saves power better than sleep mode because the device is completely powered down and therefore uses no electrical power, just as if the device is switched off. Sometimes, using this mode can cause faulty operations of some programs upon restarting due to some problems with the hibernation software; it may also terminate connections to peripheral devices. Hibernate mode is usually compared to sleep mode but sleep mode simply powers down the processing functions of the device while still consuming power to maintain the contents of the RAM for an instantaneous wake up. So while sleep mode only saves power, hibernate mode totally cuts off consumption.