A CDL job involves the operation of a large vehicle or piece of machinery, which requires a valid commercial driver’s license. There are three different classes of this license. Class A certifies a truck driver to operate vehicles whose gross weight exceeds 26,000 pounds, such as tractor-trailers, flatbeds, and tankers. Class B licenses allow someone to operate buses or box trucks, such as a furniture delivery truck or large package delivery vehicles. Class C licenses are for hazardous material transportation and passenger vans that carry 16 or more people. Positions that require a CDL often require a clean driving record and additional qualifications and skills.