Creatine is for your performance-driven athletes and while there is a lot of controversy around creatine, it is the most scientifically studied supplement to be proven safe and effective.
Creatine floods your muscles with energy, promotes nutrient uptake, and hydrates muscle tissue. It improves athletic performance drawing in nutrients to repair post training too.
To simply put it, creatine hydrates the muscle and a hydrated muscle is a healthy muscle and a healthy muscle is a high performing muscle. I mix 5 grams of creatine in my post workout protein shake every training day.