What is the principle of motor action?

Motor runs by the principle of Michael Faraday's Electromagnetic Induction. It is defined as

"when a current-carrying conductor is located in an external magnetic field perpendicular to the conductor, the conductor experiences a force perpendicular to itself and to the external magnetic field".

The direction of rotation is determined by the Right-hand Rule and is "if the right thumb points in the direction of the current in the conductor and the fingers of the right hand point in the direction of the external magnetic field, then the force on the conductor is directed outward from the palm of the right hand".