Classes are categorized depending on their site and size:

Class I: In this cavity affecting the pit and fissure on buccal and vocal surfaces of molars and premolars.

Class II: In this cavity affects the adjacent surfaces of molars and premolars.

Class III: In this cavity affects the adjacent surfaces of laterals and cuspids.

Class IV: In this cavity affects the adjacent surfaces, which include the incisal corners of the anterior teeth.

Class V: In this cavity affects one-third of the facial and lingual surfaces.

Class VI: In this cavity affecting the angular tips of molas, premolars, and cuspids.

BY Best Interview Question ON 10 Jul 2020