Dynamo = Fixed field-coils in the casing, rotating armature has multiple windings the terminations of which are diametrically opposite segments of a commutator.....each coil is positioned so that brushes contactthe segments just as the field -poles induce current on the armature......the output is DC.
the alternator is, in some senses an inside-out dynamo.-as previously stated, the armature's GENERATING FUNCTION is replaced by a stator (the casing or carcase of the machine) The rotor,as it's name suggests, rotates inside and concentric to, the stator.....often it contains residual magnetism which can "kick-off" the generation,when spun. Primarily, it uses a single winding and although it still needs slip-rings and brushes to energise the spinning rotor (field coil equivalent) the contact is continuous, therefore, unlike a dynamo, the ring/brush arrangement has a very long service life, whereas the dynamo's segments wear the brushes more rapidly. (old trick, blow conductive dust out with a blast from an airline and it sometimes revives a machine which had been "tracking-down" through excess deposits )
In all cases the ALTernator output is ALTernating current and is rectified either internally or externally (diode-pack) (a 3-phase bridge, iirc ) and a regulator which senses machine output or battery-voltage and regulates the rotor-field accordingly. (there is a slight difference between the machine and battery due to wiring/connector/battery internal resistance) Temperature can also be compensated for as it helps extend the service life of the battery.
Lucas, AC Delco, Paris-Rhone ,Ducellier and many other Alternator manufacturers use the nomenclature above (stator / rotor) I believe theirs are the correct names.