Dynamo

A term used to describe any of a variety of rotating machines that convert mechanical to electrical energy, or less commonly, electrical to mechanical  energy. Dynamos typically consist of a stationary structure, called the stator, supporting a rotating element called the rotor. Energy conversion occurs via Faraday induction. A field winding (or in some smaller machines, permanent
magnets) is mounted on one of the mechanical structures and produces a  magnetic flux. An armature winding is mounted on the other structure, and rotation of the rotor produces relative motion between the field flux and the coils of an armature winding, inducing a Faraday voltage in the armature coil. This Faraday induced voltage is the source of electrical energy at the dynamo output.