"Putting your computer in Sleep mode is like pausing your computer without closing open documents and programs. Sleep still uses a bit of power and allows you to quickly get back to work after only a few seconds. Hibernate mode is mainly for laptops because it saves your battery life. When you choose Hibernate, open documents or program settings are saved to your hard drive, and your computer switches off. Your computer takes longer to boot up from Hibernate and have the Windows desktop display, but it saves more power than Sleep."