The automobile, or motor car, is a four-wheeled vehicle intended for transportation of people and small amounts of cargo. It is usually powered by a four-stroke internal combustion engine, fueled most often with gasoline (or diesel fuel) and producing exhaust that is expelled through the tailpipe. It is contrasted with the truck (or lorry or cab) which is designed primarily for cargo and is constructed using heavier parts, and the bus (or omnibus or coach) which is designed primarily to carry passengers and may also carry small loads.
The modern automobile evolved through innovation in design, engineering, and production. The first self-propelled automobile was built by Joseph Cugnot in Paris, 1789; it had a steam-driven three-wheeled carriage. A more sophisticated version, built in 1801 by Richard Trevithick, was a heavy, three-wheeled steam carriage that could travel only 3 mph (5 kph). Karl Benz designed the Benz Patent-Motorwagen, with its four-stroke internal combustion engine, and began to manufacture them in a factory starting in 1886.
Henry Ford introduced mass production in the 1920s, lowering costs with his moving assembly line. This allowed a wide variety of consumers to afford automobiles. This new form of personal mobility opened up many possibilities, including new ways to shop, work, and play. However, automobiles came with their own problems as well: traffic jams, car accidents, and fatalities soon prompted calls for licensing, safety regulation, and more public transport. Cars are also environmentally unfriendly, releasing large quantities of greenhouse gases when they are burned for energy.