It is a protective layer spread all above the earth.  It protects us from many things like asteroids and meteoroids falling from the sky and inner threats like hazardous gases. Without ozone, layer humans will not be able to survive on earth and we will be extinct soon.  Ozone consists of a trioxide inorganic molecule that is blue in color and has a pungent smell.  The formula of ozone is O3 which also protects the earth from harmful ultraviolet rays. Overall ozone layer is very important that shields the life below from many dangers.