The oxygen that we breathe has 2 oxygen atoms in each molecule. Ozone has 3 oxygen atoms in each molecule which makes it a more powerfully oxidizing form, decaying to normal O2 in the process.
First of all, ozone is made up of three oxygen atoms. The function of this ozone is to keep out the most harmful of the Sun's rays. When struck by these rays the ozone spilts. The atoms fly around...
Ozone is created by the sun's energy. Ozone also decays fairly quickly without this energy (thus we see the "hole" above the poles when the sun can not reach this area. (yes, that does mean the hole...
Oxygen diffuses in and out of the ozone layer, and ozone decays back to oxygen. So any oxygen lost is made up... usually from the troposphere (and its nearby plants).