The sky is everything that lies above the earths surface. On our earth, the sky contains oxygen and other gases. The sky also contains clouds which are an important piece of the water cycle. If you look to the sky, you can see many things like airplanes, helicopters, hot air balloons, and in Florida sometimes, even rockets.
Humans have made full use of our atmosphere for transportation. As we venture further beyond our earth, into the dark sky of the universe, we continue to learn about the universe around us.
