and when i turn it on it will move like a common motor(i am talking about electric motors or magnetic motors)
Sounds like a motor with a very strong cobalt permanent magnet stator.
I think the motor you are referring to is called a 'servo' motor. A servo drive amplifier is used to 'hold' the motor in position, these are commonly used in robotics to keep a known position. Once the power is removed, the motor spins freely. The drive amplifier provides a voltage/current to move the motor in increments or at a certain speed. Sometimes a encoder is mechanically linked to the motor to track it's position and/or speed.
An electric servo motor with an integrated electric brake will behave like that. When the motor is disengaged, the brake will hold the motor in its last position, and the brake must be disengaged to move the motor.
An ordinary AC motor with a spring set brake works like that. When no power is applied, a spring presses brake pads against the brake rotor which is attached to the motor shaft. When power is applied, a solenoid overcomes the force of the spring and pulls the brake pads away from the brake rotor so that the motor shaft is free to turn.
Geared motors are like that. Direct drive motors with ultra strong pole magnets have very high starting torques. .
