What were the German fast troops actually during WW2?

Answer 1

I'm not sure that I understand what you mean by "fast troops". In this answer, I am assuming that you mean "land combat forces that were more mobile than foot infantry".

On that basis, the Wehrmacht's "fast troops" fell into the following classifications: -

[1] Panzer divisions: equipped with tanks, assault guns, mechanized infantry, mechanized support artillery.

[2] Panzergrenadier divisions: as for Panzer divisions, except no tanks; essentially motorized infantry with mechanized support units.

[3] Motorcycle troops: often with a sidecar; used for scouting enemy positions; for rapid reinforcement in combat; and for carrying despatches.

[4] Bicycle troops: regular infantry or cavalry, equipped with bicycles for added mobility.

[5] Fallschirmjäger: paratroops and glider-borne infantry. Most of these were actually Luftwaffe rather than Wehrmacht units.

[6] Gebirgsjäger: literally meaning "Mountain Hunter", these were infantry units especially adept at mountain warfare, in most cases capable of using skis for added mobility.

Answer 2

lets say all the units who where motorized mostly panzer and panzer grenadier units.
The German army used until the end of the war still a lot of horses

Answer 3

They were fast!