The two primary components of the air we breathe are nitrogen and oxygen. Nitrogen makes up about 78% of the Earth's atmosphere, while oxygen comprises roughly 21%. The remaining 1% consists of inert gases like argon, carbon dioxide, and trace elements. Oxygen is essential for the survival of most life forms on Earth, as it is a crucial element in the process of cellular respiration. Nitrogen, though not directly used by humans, plays a vital role in maintaining atmospheric pressure and supporting plant life through nitrogen fixation.