Terminology
The parts of an alternator or related equipment can be expressed in either mechanical terms or electrical terms. Although distinctly separate, these two sets of terminology are frequently used interchangeably or in combinations that include one mechanical term and one electrical term. This may cause confusion when working with compound machines such as brushless alternators, or in conversation among people who are accustomed to work with differently configured machinery.
In alternating current machines, the armature is usually stationary, and is known as the stator winding. In DC rotating machines other than brushless DC machines, it is usually rotating, and is known as the rotor. The pole piece of a permanent magnet or electromagnet and the moving, iron part of a solenoid, especially if the latter acts as a switch or relay, may also be referred to as armatures.
Mechanical
Rotor: The rotating part of an alternator, generator, dynamo or motor.
Stator: The stationary part of an alternator, generator, dynamo or motor
Electrical
Armature: The power-producing component of an alternator, generator, dynamo or motor. The armature can be on either the rotor or the stator.
Field: The magnetic field component of an alternator, generator, dynamo or motor. The field can be on either the rotor or the stator and can be either an electromagnet or a permanent magnet.
Read more about this topic: Armature (electrical Engineering)