Arthropods have jointed legs which means that:

Explanation

Jointed appendages allow arthropods to have much greater flexibility and range of movement. Most of the exoskeleton in the body of arthropods is hard but it is softer and more bendable at these joints, which allows movement. In general, it is for protection but it also serves as a lever for the movement of muscles of jointed limbs. The chitin in the jaws is used for biting and crushing food. It also forms the lens of the compound eyes the copulatory organs and organs of defense and offense.