As we discussed with Solar radiation, something happens in between the top of the atmosphere and the surface of the Earth. It's main function is to absorb UV light from the incoming light from the Sun.
Ozone is actually three oxygen atoms bonded together.
When a UV ray hits the ozone molecule it breaks apart. Then we get one O 2 molecule and one O atom. The Oxygen is traded around in the ozone layer so there is always more being created. Recently you may have heard scientists talking about the ozone layer shrinking. They used satellites and found an area over Antarctica where there is actually a big hole.