Imperial Scout Troopers were elite stormtroopers. Usually stationed where other members of the Stormtrooper Corps was stationed, they provided service as scouts (hence their name), spies, snipers, and artillery backup. Because of the use of speeder bikes while scouting, scout troopers have earned the nickname "biker scout" from Rebel troops.
During the Clone Wars, Clone Scout Troopers served as scouts in the 41st Elite. At first, they were limited to just jungle environments while ARF Troopers served everywhere else.
After the Clone Wars ended, the Clone Scout Troopers were turned into Imperial Scout Troopers and served alongside human recruits.