The Servo Motor allows robot to move and interact with its surroundings, and provides the motion capabilities to your robot. The Servo Motor has a built-in rotation sensor that measures speed and distance, and reports back to the NXT Brick. The in-built rotation sensor can count the number of rotations the motor is taking. This allows for motor control within one degree of accuracy. There is infinite usage of motors, e.g. moving car in a car robot, lifting motion to crane robot, and so on. . This is the component that we will need in almost all the models.
When you set a Move or Motor blocks' direction, you are specifying the direction the motor will spin. This may be different than the direction your robot actually moves. Depending on how you place motor into your robot, setting the motors to go forwards may cause your robot to move backwards.