Automobiles are four-wheeled motor vehicles designed primarily for passenger transportation, usually propelled by an internal combustion engine using a volatile fuel. Modern automobiles are complex technical systems, with thousands of subsystems with specific design functions. They can be powered by a variety of engines, including gasoline (carburetor internal combustion), diesel, electric, or gas turbine. They also use a variety of power transmission systems, from a simple chain drive to an advanced all-wheel drive system. The body of an automobile encloses the mechanical parts and provides passengers with protection, while the chassis, or frame, supports it and transmits the power from the engine to the wheels.

The automobile has revolutionized the way people live and work. It has made it possible for people living in cities to travel to the countryside and vice versa, and to have a flexible schedule that allows them to take time off from work for leisure activities. It is a convenience that has transformed society and boosted the economy.

Inventors first began to perfect the modern automobile toward the end of the nineteenth century, with inventors such as Gottlieb Daimler, Karl Benz, and Nicolaus Otto receiving patents for their designs. Known by several names in early media, including autocar, motor car, and automobile, the automobile was considered an experimental machine at its inception.

After the invention of the automobile, many companies raced to develop production methods that would allow it to be affordable for middle-class families. Henry Ford succeeded in this effort by developing assembly lines at his factories, which significantly reduced the price of the Model T runabout until it became a mass-produced vehicle.

Today there are more than 3 trillion miles (5 trillion kilometers) traveled on the world’s roads by cars. Most of them are passenger cars, with the most common type being the sedan. Other types include the coupe, minivan, and SUV. There are also special automobiles, such as those used by police and fire departments, as well as for hauling cargo.

A typical automobile has a number of safety features, such as air bags and seat belts. In almost every country, drivers and passengers must fasten their seat belts while riding in the car. Infants and children must be secured in child seats. Other safety measures include reducing speed limits, and avoiding distractions while driving.

The car is the most commonly used mode of transportation in the world. It is a convenient and efficient means of transport, especially in urban areas where public transit is difficult to access. However, it can be expensive to own and maintain a car. Some people may choose to rent a car when traveling for business or pleasure. This can help them save money on gas and maintenance costs, and it can provide flexibility in scheduling. It can also reduce reliance on other people for transportation.