Movable joints, also known as synovial joints, are connections between bones that allow for a wide range of motion. They are characterized by a joint capsule filled with synovial fluid, which lubricates the joint and reduces friction. Common types of movable joints include hinge joints, like the elbow, and ball-and-socket joints, like the shoulder. These joints are essential for various body movements, enabling activities such as walking, running, and lifting. The structure of movable joints includes cartilage, which cushions the bones, and ligaments, which provide stability. Proper functioning of movable joints is crucial for overall mobility and physical health.