The Earth's atmosphere is a dynamic envelope of gases held in place by gravity, crucial for sustaining life and regulating global climate. Its composition varies with altitude, but it primarily consists of nitrogen ($\text{N}_2$), oxygen ($\text{O}_2$), argon ($\text{Ar}$), and trace amounts of other gases like carbon dioxide ($\text{CO}_2$). This gaseous layer is stratified into several distinct regions, including the troposphere, where most weather phenomena occur; the stratosphere, which contains the protective ozone layer; the mesosphere; and the thermosphere. These atmospheric layers interact with solar radiation and Earth's surface, mediating temperature fluctuations and shielding the planet from harmful cosmic radiation.