Creatine is a natural substance found in commonly consumed foods like meat and fish. It may very well be the most researched supplement on the planet; it may also be one of the most proven to be effective in helping both athletes and normal folks like you and me.
Creatine is a supplement that requires saturation. It is a cumulative- rather than acute- supplement, meaning your body will respond to it if you allow it to "build up" in your body.
Most of the creatine your body stores, is held directly in your muscle, making it readily available for energy and ATP production (used to contract muscles.
Creatine products vary in the their formulas and taste. You can also buy creatine in either pill or capsule form.
Because your muscles use creatine to create muscle-contracting energy, using a creatine supplement can help develop strength and with recovery. Recent studies also show a promising correlation between creatine supplementation and slwoing of the aging process. So everyone, it seems, can benefit to some degree from creatine usage.
Like with all supplements, it's wise to do your own research and consult with your physician. For most of my supplements, I use my sponsored company, dotFit.
I trust dotFit because of their extensive research. It's founder, Neil Spruce, formerly owned and headed NASM (National Academy of Sport Medicine), the most recognized and respected body for sports medicine and training. They are also one of the few companies I've seen or heard of whose products are NSF* Certified. Simply put, that means they guarantee the permissible usage of their products by collegiate and pro athletes.
But, again, feel free to find a product to your taste in cost and flavor.