In the fictional Star Wars universe, BARC Troopers are an elite group of Republic clone scouts.
BARC Troopers, (BARC stands for Biker Advanced Reconnaissance Commando) are specially trained clone commandos and scouts. During the height of The Clone Wars, BARC Troopers were dispatched to such planets as Kashyyyk. Following the execution of Order 66 and the rise of the Empire, it is largely the elite, camouflaged BARC Troopers of the Republic that evolved into the less-advanced Scout troopers of the Galactic Empire.

Like the later Imperial Scouts, the BARC Troopers are primarily dispatched on ground-based mission. They wore lighter armor, and their gear incorporated comlinks, breathing gear, and macrobinocular lenses. They generally used lighter, more portable weapons than Imperial Scouts.

However, unlike the lightly armed and armored Speeder Bikes used by the Empire in later years, the BARC Troopers, who primarily saw action on Kashyyyk, the Wookiee homeworld, used the fast, highly agile BARC Speeder Bike, which was both better armored and better armed than later Bikes used by the Empire, though it lacked the saddlebags mounted to the side. Presumably, the Emperor decided to cut back costs by using less expensive bikes, or is another example of the relatively low regard placed on soldiers lives.
Another difference is that while Imperial Scouts, like all other stormtroopers, wore white armor over a black body-glove, the BARC Troopers wore camouflage-colored armor, in tones of green and brown. An exception to this was on the planet of Saleucami, where the BARC troopers donned typical white armor with an unusual, beak-like structure affixed to the front of their helmet.