What is known as a hard outer supportive system?

A hard outer supportive system is often referred to as an exoskeleton. Exoskeletons are external structures that provide support and protection to an organism, commonly seen in arthropods like insects and crustaceans. They serve to maintain shape, protect against environmental hazards, and reduce water loss, enabling these organisms to thrive in various habitats. In engineering and robotics, exoskeletons can also refer to wearable devices that enhance human strength and mobility.