Diarthrosis refers to a type of joint in the human body that allows for a wide range of motion. These joints are characterized by a fluid-filled cavity, known as the synovial cavity, which provides lubrication and reduces friction during movement. Common examples of diarthrosis joints include the knee, elbow, and shoulder. Diarthrosis joints are classified into several subtypes based on their movement capabilities, including hinge, ball-and-socket, and pivot joints. The structure of these joints enables activities such as bending, rotating, and gliding, making them essential for daily movements and physical activities.