Bruce has a computer that he puts into hibernation, but when he unplugs it, it shuts down. Leo says the there's a difference between hibernation and sleep mode. Sleep keeps the computer on, but loads everything into RAM and shuts down the hard drive and other things it doesn't need. It's in an extreme low power mode, but keeps refreshing the RAM so it'll come back on when woken up. Hiberation, on the other hand, completely shuts down the computer and then writes the RAM contents to the hard drive to access when it's turned back on.
Leo says he's not a fan of hibernating. It doesn't really work all that well. Some computers and tablets simply can't wake up from it. He recommends allowing it to go to sleep if he's going to get back to it within 24 hours. Then shut it down if he won't be using for longer than that.