Carbon credits are like an imaginary currency that can be used to help reduce the amount of skin damaging carbon dioxide that gets into the air. It works like this: businesses, factories and other places that make a lot of carbon dioxide can buy carbon credits from businesses that are reducing their carbon dioxide output. This is like trading money - the business that is reducing their carbon dioxide output gets money from the businesses that are making a lot of carbon dioxide, and the business that is making the carbon dioxide gets what we call "carbon credits" that it can use to reduce their output. In a way, it's like paying someone else to clean up your mess.