(i) It absorbs ultraviolet radiations from sun and prevents them from reaching on the earth's surface causing damage to life.
Identification : ultraviolet radiations one correct application (= sanitization, forensics)
(ii) Water molecules present in most materials readily absorbs infra red waves. Hence, their thermal motion increases. Therefore, they heat their surroundings.
They are produced by hot bodies and molecules. Incoming visible light is absorbed by earth's surface and radiated as infrared radiations. These radiation are trapped by green house gases.