For better or worse, we simply can't live without sleep. It's an essential function that helps us recharge our body's batteries, stay healthy and alert, and keep our brain doing what it needs to do. Dreaming can help us face and process issues in our waking lives. But what is sleep, beyond a state in which your body and mind can regenerate? Why do we do it? How much do we need? If you're someone who has asked yourself these questions—or if you struggle with sleep issues—this collection is for you. You'll get the basics on sleep, how to improve your sleeping habits, and tips on how to beat insomnia.