The main component of the Earth's atmosphere is nitrogen, comprising about 78% of the atmosphere by volume. Oxygen follows, making up approximately 21%, while other gases such as argon, carbon dioxide, and trace gases account for the remaining 1%. Nitrogen is inert and plays a crucial role in processes like the nitrogen cycle, while oxygen is essential for the survival of most life forms on Earth. The composition of the atmosphere is critical for maintaining temperatures, supporting life, and fostering weather and climate processes.