A robotic arm is a type of mechanical arm, usually programmable, with similar functions to a human arm; the arm may be the sum total of the mechanism or may be part of a more complex robot. The links of such a manipulator are connected by joints also allowing either rotational motion or because of translational displacement.
The robot uses motion sensors so to make sure it moves just the right amount. An industrial robot with six joints closely resembles a human arm — it has the equivalent of a shoulder, an elbow and also a wrist.