A sea turtle is a type of reptile belonging to the order Testudines. Specifically, sea turtles are marine reptiles adapted to life in the ocean. There are several species of sea turtles, such as the loggerhead, green, and leatherback. They are characterized by their streamlined bodies, flippers, and hard shells, which provide protection. Sea turtles play vital roles in their ecosystems, such as maintaining healthy seagrass beds and coral reefs. They are long-lived creatures that can migrate long distances and are currently threatened by habitat loss and human activities.