A mollusk is a type of soft-bodied animal that belongs to the phylum Mollusca. They are known for their diverse forms and habitats, ranging from the ocean to freshwater and even land. Common examples of mollusks include snails, clams, and octopuses. Most have a hard shell that protects their body, although some, like octopuses, do not. Mollusks play important roles in ecosystems and human life. They can be found in various environments, contributing to the food chain and serving as a food source for many animals, including humans. Additionally, some mollusks, like oysters, are valued for their pearls and are harvested for culinary purposes.