Our planet's unique atmosphere contains four distinct layers.  These layers are divided vertically on the basis of temperature.  The different layers alternate between regions of increasing temperature and decreasing temperature with height.  (If you are not familiar with how pressure behaves in the atmosphere click here for a quick lesson.)
The figure below shows how temperature varies with altitude in the atmosphere.  The x-axis represents temperature in degrees Celsius and the y-axis represents altitude.  Note the alternating regions of decreasing and increasing temperature with height.  An inversion exists when temperature increases with altitude.  The figure below shows the four layers: the Troposphere, the Stratosphere, the Mesosphere, and the Thermosphere.  Between each layer exists a "pause" in which the temperature remains constant with height.

The atmosphere is a layer of gases that surrounds the Earth. It has five primary layers.


The troposphere is the lowest layer of the atmosphere. It is where we live and where most of our weather occurs. This layer is about 7 miles thick and contains about 80% of the total mass of the atmosphere.


The stratosphere is above the troposphere and is about 30 miles thick. It contains the ozone layer, which helps protect us from the sun's harmful UV rays.


The mesosphere is above the stratosphere and is about 50 miles thick. This layer is where meteors burn up when they enter the Earth's atmosphere.


The thermosphere is above the mesosphere and is about 300 miles thick. This layer is where the Northern and Southern Lights occur.


The exosphere is the outermost layer of the atmosphere. It is where satellites orbit the Earth and is about 6,200 miles thick.

Each layer has unique properties and characteristics that are important for our understanding of the Earth's atmosphere.