A truck or lorry is generally a large motorized vehicle used to transport freight, carry heavy payloads, or do other utilitarian function in the transport industry. Trucks differ greatly in size, speed, and configuration, although most trucks feature independent body-on-axle construction. Trucks can be either internal combustion engines or electrics, or a combination of engine and transmission. Most trucks are powered by internal combustion engines, although there are hybrid versions of the truck that run on electric motors. Some trucks are powered by electrics, which have lower fuel consumption than internal combustion engines.

Trucks are classified into three broad categories according to how they are powered. Flatbed trucks are passenger vehicles that have a boxy design, generally with a cab that seats five people. Most flatbed trucks have between two and eight axles, depending on the model. Longtail and utility trucks are utility vehicles that have an enclosed cab with an attached semi-trailer. Longtail and utility trucks also have an open cab that has a short bed, sometimes topped off with a semi-trailer.

Another classification is long-bed or full-sized pickup. This type of vehicle is normally mid-sized or larger and has between six to eight axles. There are also large pickups known as box trucks that have between ten to fifteen axles. The smallest pickup is known as a folding pickup. These vehicles have a capacity for carrying only passengers or cargo.

General-utility trucks are typically small, single-wheeled vehicles with at least one double-cylinder engine and one gasoline engine. They have a wide range of different designs such as four-wheel drive, high-performance models that are able to cross the country with relative ease, and small utility vehicles to help with hauling goods from the house to the store. General-utility pickups are usually small vans that are powered either by a diesel engine or an electric motor.

The third type of truck is a heavy-duty truck. A heavy-duty truck is any vehicle with a capacity greater than that of a medium-sized car. Medium-sized cars can carry a lot of items, but are generally too heavy for some drivers to handle easily. A heavy-duty truck is able to pull or push a car, boat, trailer, or an RV; however, it usually requires more strength than the latter to lift or push. This makes them difficult for younger or inexperienced drivers to handle because they strain the body and increase the chance of a fatal accident. Heavy-duty trucks are ideal for construction and other work that requires a lot of strength.

An important aspect of trucking is the fuel or diesel that the truck uses. It is estimated that in the United States, the fuel consumed by passenger cars and trucks is almost double that of trucks. This makes trucks a large contributor to global warming. Diesel, which is derived from crude oil, has a high carbon monoxide content that contributes to global warming. The trucking industry has been pushing for stricter regulations on the amount of diesel that may be used, so it is doubtful that this problem will be addressed any time soon.

Lastly, there are utility vehicles. These are typically smaller passenger cars that are used for things such as hauling garden tools, lawnmowers, pool chemicals, sand and water, and light trucks. Sport utility vehicles are also sometimes classified as utility vehicles, but this title is often applied to vehicles such as golf carts and smaller passenger cars. Smaller sport utility vehicles tend to have better gas mileage and are easier to repair when needed.

Towing a semi-trailer truck, an 18-wheeler, tractor, or other large truck is an experience that every driver should be prepared for. While larger trucks usually carry the weight of several people and cargo, the weight of a single vehicle carrying the weight of several people can cause severe back, neck, and wrist pain. Because of this, many drivers who own larger trucks and transport goods in addition to passengers, opt to purchase a truck that is powered by an electric engine, has an electronic breakdown system, has airbags on board, or at least features standard tows.