There are four main types of bones in the human body: long bones, short bones, flat bones, and irregular bones. Long bones, like the femur and humerus, are longer than they are wide and support weight. Short bones, such as those in the wrist and ankle, are roughly cube-shaped and provide stability. Flat bones, including the skull and sternum, serve protective functions and provide surfaces for muscle attachment. Irregular bones, like the vertebrae and pelvis, have complex shapes that fulfill various roles in the body. Each type of bone contributes to the overall structure and function of the skeletal system.