A CDL, or Commercial Driver's License, is a special type of driver's license required in the United States for individuals who operate large or heavy vehicles. This includes trucks, buses, and vehicles that transport hazardous materials. Obtaining a CDL ensures that drivers have the necessary skills and knowledge to safely operate these vehicles on public roads. To get a CDL, applicants must pass both written and driving tests that assess their understanding of traffic laws and vehicle operation. There are different classes of CDLs, such as Class A, Class B, and Class C, each allowing the driver to operate specific types of vehicles.