Degrees of freedom refer to the number of independent coordinate axis movements possessed by a robot, and should not include the opening and closing degrees of freedom of the gripper (end tool). Describing the position and posture of an object in three-dimensional space requires six degrees of freedom, position operations require three degrees of freedom (waist, shoulder, elbow), and posture operations require three degrees of freedom (pitch, yaw, roll).
The degrees of freedom of industrial robots are designed according to their purpose, which may be less than 6 degrees of freedom or greater than 6 degrees of freedom.