Automobiles, formerly known as motorcars, are vehicles that are self-propelled on land. These are one of the most popular and versatile forms of transportation on Earth.

During the 20th century, automobiles became widely available and have become an essential part of most developed societies. About 1.4 billion automobiles are in use worldwide, and about 70 million new ones are built each year.

In the early years, cars were mostly made in Europe and the United States. In the United States, the industrial revolution led to new mass-production techniques that reduced the cost of manufacturing cars. Henry Ford was able to use these techniques to produce the Model T, the first car that was affordable for the general public.

By 1920, the automobile had overtaken horse-drawn carriages as the preferred form of transportation in both Europe and the United States. This was a result of the growth in population and the need to transport goods over large distances.

The development of the automobile in Europe started with the introduction of the internal combustion engine by German inventor Karl Benz in 1885. He patented the design of his Benz Patent-Motorwagen in January 1886. He produced and sold several copies of this vehicle, which was powered by a four-stroke engine of his own design.

He also developed an accelerator for speed regulation, a battery ignition system, a spark plug, a clutch, a gear shift and a radiator. His inventions laid the foundation for modern automobile engineering.

Later, a number of engineers and manufacturers improved on the design of the automobile to meet changing consumer demands for fuel efficiency, safety and comfort. The development of the gasoline engine, in particular, ushered in the era of the American car.

Today, automobiles are manufactured all over the world using a wide variety of materials and components. They are categorized into various types, according to their purpose of use: Passenger vehicle (car, bus, truck), commercial vehicle and special-purpose vehicle (ambulance, firefighter, police vehicle).

An automobile is usually driven by a gas or diesel engine that is located in the front of the vehicle. This power is transmitted to the wheels either by a transmission system or directly from the engine. Some engines are mounted in the rear of the vehicle, though these are less common.

Automotive engines come in many forms, ranging from a simple overhead camshaft to a complex piston-based, valve-controlled, electronic gasoline engine. Most vehicles are fueled by gasoline, although some use diesel or CNG.

The modern automobile has evolved into a highly sophisticated technological system with thousands of component parts. The main subsystems are the body, chassis, engine, drivetrain, control systems and emission control systems.

Some important features of an automobile are the steering wheel, brakes, suspension and seat. The body can be made of steel, aluminum, plastic or fiberglass, and the seats can be leather, fabric, cloth or vinyl. The engine can be water-cooled or air-cooled.

The driving system of an automobile determines how much power the engine can supply to the wheels and whether the wheels are independent or a two-wheel drive. The transmission can be a belt, chain, or gears. The belt-driven transmission is the most common system, although a manual transmission has been in existence for over 200 years.