What is the group name for animals live in shells?

Animals that live in shells are commonly referred to as "mollusks." This diverse group includes organisms such as snails, clams, and octopuses, many of which possess a hard external shell for protection. Mollusks are characterized by their soft bodies and, in many cases, a muscular foot used for movement. Other shell-bearing animals, like certain crustaceans, may also be considered but are not classified as mollusks.