The basis for the division of the atmosphere into several regions is temperature. The temperature of the atmosphere decreases with increasing altitude. This decrease in temperature is known as the vertical temperature gradient. The vertical temperature gradient is not uniform, but rather varies with altitude. This variation in the vertical temperature gradient is responsible for the formation of different layers of the atmosphere.

The different layers of the atmosphere are:

- The troposphere

- The stratosphere

- The mesosphere

- The thermosphere

- The exosphere

Each of these layers has a characteristic temperature profile and composition. The troposphere is the lowest layer of the atmosphere and contains most of the mass of the atmosphere. The stratosphere is the layer above the troposphere and is characterized by a relatively constant temperature gradient. The mesosphere is the layer above the stratosphere and is characterized by a very low temperature gradient. The thermosphere is the layer above the mesosphere and is characterized by a very high temperature gradient. The exosphere is the outermost layer of the atmosphere and is characterized by a very low density of particles.