Final answer:
The key distinction between four-wheel-drive and all-wheel-drive systems lies in how they engage and distribute power to the wheels.
Step-by-step explanation:
The key distinction between four-wheel-drive and all-wheel-drive systems lies in how they engage and distribute power to the wheels. A four-wheel-drive system typically requires manual activation and is commonly found in off-road vehicles or trucks. On the other hand, all-wheel-drive systems engage all four wheels constantly and are commonly found in passenger cars and SUVs for improved traction and stability on various road conditions.