1. A teaching and playback method for a robot, comprising: performing by a processor a teaching and playback operation based on inverse kinematics for the robot, for posture control in operational space, by calculating joint angles of the robot in joint space using end-effector parameters and a redundancy resolution parameter of the robot, wherein the redundancy resolution parameter is determined in conjunction with a joint structure of the robot and the redundancy resolution parameter is an arm angle which is an angle between a set reference plane and an arm plane formed by a shoulder, elbow and wrist of the robot.