A Commercial Driver License allows people to operate heavy-duty vehicles. Generally speaking, there are 2 Classes of CDL’s: Class A and Class B.
A Class A license is required to operate the big trucks that pull long trailers that you see on the highways. A big truck that pulls a long trailer is called a Combination Vehicle because it is a combination of 2 vehicles (1 truck and 1 trailer). These vehicles deliver most of the goods that people purchase from stores, such as food and beverages, furniture, building supplies, toys, cars and trucks, clothing, flowers…everything! Everything that you see in your home, including the materials that were used to build your home, was delivered to a store by these big combination vehicles. The trucks that pull the long trailers must be very powerful because a fully-loaded trailer can weigh as much as 65,000 pounds. The trucks can weigh between 15,000 and 20,000 pounds. These big trucks can also have as many as 18 speeds! Most cars have just 6 speeds.
A Class B license is required for big vehicles that do not pull a trailer, such as school buses, cement mixers, and big trash trucks.