That looks a logical explanation. So does that mean that the sleep mode consumes less energy to that of the hibernation mode?
No, it's the opposite. As I said in my previous post, hibernation is a fully powered down state. In other words, you can unplug the computer, after it's gone into hibernation, and not lose any of your last work session (that you saved when the computer went into hibernation) when you restore power. In contrast, sleep (sometimes also called Standby) mode does require some power. If you unplug a computer in sleep mode, you will lose whatever apps/programs/windows you had open when it went to sleep. For example, if you had a web browser open with 10 tabs open and a word processing program/app open when the computer went to sleep and you pulled the plug on it, you'd lose your work session; it would not be restored upon restoring power and starting your computer again. But, with hibernation, you would not lose your work session; it would be restored the next time your turn on your computer.
Note: hibernation does
momentarily require more power when it is saving a session, compared to going into to sleep mode. Sleep mode occurs immediately when it is invoked. Hibernation takes a minute or two or longer, depending on your hardware specs and system configuration, because it saves a complete image of your work session to the hard drive.