It is everything above the stars and planets. It's used 274 times. It includes the air we breathe, outer space, the limits of the universe, and the highest heaven, the dwelling place of God. There is not a place in the skies that He did not create. Let's begin with out own atmosphere.
Many planets have atmospheres of some gaseous mixture.
This mixture of gases is exactly what humans, animals, trees and plants need to exist. Without air, there could be no life on earth. Air shields the earth from harmful solar rays and objects from outer space hitting earth. Air traps heat from the sun, giving earth enough heat to support life. Air also makes it possible for sound to travel to our ears.