4WD, or four-wheel drive, is a vehicle system that powers all four wheels simultaneously. This feature enhances traction and stability, making it ideal for off-road driving and challenging terrains, such as mud, snow, or rocky surfaces. Vehicles equipped with 4WD can better navigate difficult conditions compared to standard two-wheel drive vehicles. There are two main types of 4WD: full-time and part-time. Full-time 4WD, often found in vehicles like SUVs and trucks, automatically distributes power to all wheels at all times. Part-time 4WD allows the driver to switch between two-wheel and four-wheel drive, providing flexibility for different driving conditions.