What process contributed to the formation of Earth's early atmosphere?

The formation of Earth's early atmosphere was primarily influenced by volcanic outgassing, which released gases such as water vapor, carbon dioxide, nitrogen, and methane. As the planet cooled, water vapor condensed to form oceans, while volcanic activity continued to release gases into the atmosphere. Additionally, impacts from comets and asteroids may have contributed volatile compounds, further shaping the atmospheric composition. Over time, these processes laid the foundation for the development of a more stable atmosphere and the emergence of life.