The layer of gas surrounding the Earth is called the atmosphere. This protective envelope of gases is essential for sustaining life, providing vital elements such as oxygen for breathing and carbon dioxide for plants' photosynthesis. The atmosphere also plays a crucial role in regulating the planet's temperature through the greenhouse effect and shielding Earth from harmful solar radiation. Composed of multiple layers—including the troposphere, stratosphere, mesosphere, thermosphere, and exosphere—the atmosphere transitions into outer space. Understanding its composition and dynamics is critical for addressing issues like climate change and air quality.