Ozone present in the stratosphere is called good ozone.

Explanation

(1) The ozone present in the upper atmospheric region, i.e. in the strosphere, absorbs the ultraviolet radiations present in the sunlight.
(2) These radiations are harmful for living organisms.
(3) Ozone protests the living organisms from such dangerous UV radiations.
(4) The ozone present in the stratosphere is, therefore, called good ozone.