The Ozone layer is part of the Earth’s atmosphere.  It is also less commonly known as "ozonoshpere layer".  The Ozone Layer has a relatively high concentration of ozone (O₃).  "Relatively high" refers to a few parts per million. The concentration is much lower in the lower atmosphere.  The Ozone layer is found in the Stratosphere which is10-50km above the Earth’s surface.  The Stratosphere is a layer of the Earth's Atmosphere that is arranged in layers of temperature, with warmer layers higher up and cooler layers farther down.

 The ozone layer protects us and the environment against UV (ultraviolet) rays or radiation from reaching the earth.  The UV radiation has enough energy to break covalent bonds.  If the UV radiation were to reach earth, it would have the power can cause chemical changes resulting is sunburns linked to cataracts and skin cancer and also damage DNA which causes mutation and can destroy vegetation.