How do bad and good ozone form

Bad ozone is an air pollutant that is harmful to breathe and it damages crops, trees and other vegetation. The stratosphere or "good" ozone layer extends upward from about 6 to 30 miles and protects life on Earth from the sun's harmful ultraviolet (UV) rays. So, to sum it up good ozone forms in the earth's atmosphere naturally. While bad ozone forms by chemical reactions through emissions.

(Hope this helps) Sky

lithosphere and asthenosphere