The document summarizes basic human skeletal anatomy and function. It describes how the 206 bones of the average adult skeleton form a protective framework that is joined by ligaments and tendons. It also discusses the main functions of the skeleton, including movement, organ protection, blood cell production, and mineral storage. Additionally, it provides details on the four main types of joints - ball and socket, hinge, pivot, and gliding - and defines the terms used to describe different joint movements like extension, abduction, adduction, and rotation.