4WD stands for “four-wheel drive.” It is a drivetrain system that sends power to all four wheels of a vehicle, instead of just the front or rear wheels. This allows for improved traction and stability on a variety of surfaces, including loose gravel, mud, snow, and other low-friction environments. It also provides additional traction, especially when transporting heavyweight loads up a steep incline. It is also known as 4×4 (four by four) meaning 4 wheels drive the vehicle. This type of drivetrain is commonly found in trucks, SUVs, and off-road vehicles, but can also be found in some passenger cars.