A skeleton is the internal framework of an organism, composed of bones and cartilage, that provides structural support, protection for vital organs, and facilitates movement in conjunction with muscles. In vertebrates, it is typically divided into two main parts: the axial skeleton (including the skull, vertebrae, and ribcage) and the appendicular skeleton (comprising the limbs and pelvic girdle). In some contexts, "skeleton" can also refer to an incomplete or reduced structure in organisms or a figurative representation in various fields.