Air? Air is a general term. Air is composed of many elements like carbon, nitrogen, oxygen etc. Oxygen is the air we breathe and basically we can't live without it.
Air aka oxygen is the main thing along with water that is needed to sustain life. Now as for air per se is air compressors and tools, air to inflate toys and things, Planes need air flow to fly, storms use the air flow so air is very important in every day life
In our daily lives, we need plenty of air to breathe! Our planet’s air itself is, of course, a mixture of gases. Nitrogen forms about 78 percent and oxygen about 21 percent, the rest being minute quantities of argon, carbon dioxide, helium, and so forth. Remarkable processes work to keep that mixture free from change.
As Time magazine says: “With uncanny precision, the mixture [is] maintained by plants, animals and bacteria,” which use and return the gases at equal rates. “The result is a closed system, a balanced cycle in which nothing is wasted and everything counts.” This is , indeed, amazing! Carbon dioxide, for example, forms only about one part in every three thousand parts of air by volume. When men and animals breathe air they use the oxygen and exhale carbon dioxide. But plants do the opposite. They take in carbon dioxide and give off oxygen, maintaining the balance.