Automobiles are vehicles that can drive themselves, without relying on an outside power source such as horses or human power. These vehicles have greatly changed the way people live in the modern world, providing a sense of freedom and convenience not previously available to many. The automobile also has contributed to the growth of numerous industries related to transportation, including gas stations, car dealerships, and auto parts shops. It is estimated that Americans drive over three trillion miles per year in their cars.

Exactly who invented the automobile is a matter of some dispute, but it seems clear that the first gasoline-powered motor car was created in 1885 or 1886 by Karl Benz of Germany. Benz’s design was based on a flat engine, which used an internal combustion process to create mechanical energy that could be transmitted to the wheels. This mechanical energy allowed the car to move forward or backward and climb hills, and it was controlled by a simple clutch and brake system.

The earliest automobiles were essentially horse-drawn carriages with engines added. As the technology improved, however, these cars became more sophisticated, and it was not long before modern life seemed inconceivable or at least highly inconvenient without access to an automobile. The invention of the automobile caused entire societies to restructure themselves around the ease of travel and long-distance movement that it made possible. It also helped to give rise to new leisure activities such as travel, sports, recreation, and restaurants, and it brought with it new laws and government requirements, including safety features, highway rules, and drivers’ licenses. It also contributed to suburban sprawl, where families moved away from city centers into house and garage-built homes surrounded by green lawns.

The modern automobile consists of thousands of individual parts, and these are arranged into semi-independent systems that perform different functions. For example, the engine—the “heart” of the automobile—consists of cylinders, pistons, tubes to deliver fuel to the cylinders, and an electrical system to control the operation of the car’s engine, as well as other components. The arrangement, choice, and type of the parts vary according to a vehicle’s intended use. For example, a car designed for economy may be more focused on the efficiency of its engine and transmission than on comfort and handling, while a racing car will require a stronger engine and more fuel to be able to sustain high speeds.

The advent of mass production techniques in the early twentieth century further reduced the cost of automobiles and brought them within reach of middle-class households, particularly in the United States. Henry Ford, for example, invented the assembly line, which revolutionized industrial manufacturing and lowered the price of his Model T until it was affordable to most Americans. Other manufacturers quickly followed suit.