leep gives your body a rest and allows it to prepare for the next day. It's like giving your body a mini-vacation. Sleep also gives your brain a chance to sort things out. Scientists aren't exactly sure what kinds of organizing your brain does while you sleep, but they think that sleep might be the time when the brain sorts and stores information, replaces chemicals, and solves problems.
Skipping 1 night's sleep makes a person cranky and clumsy. After missing 2 nights of sleep, a person will have problems thinking and doing things; his or her brain and body can't do their normal tasks nearly as well. After 5 nights without sleep, a person will hallucinate (this means seeing things that aren't actually there). Eventually, it becomes impossible for the brain to give its directions to the rest of the body without sleep — the brain needs to spend time in bed and catch its ZZZs!
I love google. Couldnt be nothered writing it myself lol