A steering wheel is a circular device used in vehicles to control their direction. When a driver turns the steering wheel, it adjusts the angle of the front wheels, allowing the vehicle to navigate left or right. Steering wheels are typically made of materials like plastic, metal, or leather and may include features such as buttons for audio controls or cruise control. Most modern vehicles, including cars and trucks, have power steering systems that make it easier to turn the wheel. This system can be hydraulic or electric, providing assistance based on the driver's input. The design and size of steering wheels can vary, but they are essential for safe driving and maneuverability.