Seashells are the hard, protective outer coverings created by marine animals known as mollusks. These shells come in various shapes, sizes, and colors, depending on the species of mollusk that produced them. Common types of mollusks that create seashells include snails, clams, and oysters. Seashells serve as a defense mechanism against predators and environmental factors. Seashells are often found on beaches and are popular among collectors and artists. They can be used in crafts, jewelry, and home decor. Additionally, seashells play a role in the ecosystem, providing habitats for small creatures and contributing to the formation of beach sand.