The main component of air is nitrogen, which constitutes about 78% of the Earth's atmosphere. In addition to nitrogen, air is composed of approximately 21% oxygen, along with trace amounts of argon, carbon dioxide, and other gases. The balance of these components is essential for maintaining life on Earth, as oxygen is crucial for respiration in living organisms. Nitrogen, while not directly used by most organisms, plays a significant role in the environment, particularly in the nitrogen cycle, contributing to the growth of plants and the overall ecosystem.