What is the "OZONE LAYER"

Some one can be think the ozone is a small strata. but, it isn't truth.  The ozone layer is
big strata.It is in the strata sphere encircling 
the earth.

The much of the harmful ultraviolet radiation comes from the sun.also ultraviolet radiation 
that from the ozone in the first place.

Ozone is special from of oxygen made up of
three oxygen atoms rather than the usual to oxygen atoms. It usually 
from when sun type of radiation or electrical discharge close the two
atoms in an oxygen molecule  (O2)  which can then individually recombine with other (o2) molecules to from ozone (o3).