Turtles and tortoises are both reptiles with shells, but there are some key differences between them. Turtles are generally aquatic or semi-aquatic, with webbed feet for swimming, while tortoises are land-dwelling and have stumpy feet for walking on land. Additionally, turtles have flatter, more streamlined shells for swimming, while tortoises have domed shells that provide protection on land. Overall, the main difference lies in their habitat and adaptations for living either in water or on land.