What is the difference between external and internal skeleton structures?

External skeletons, or exoskeletons, are rigid structures that provide support and protection from the outside, commonly found in arthropods and some mollusks. In contrast, internal skeletons, or endoskeletons, are located within the body and provide support and shape, as seen in vertebrates like mammals, birds, and reptiles. While exoskeletons can limit growth until molting, endoskeletons allow for continuous growth and development. Each type of skeleton serves to protect vital organs and facilitate movement in different ways.