Automobiles are powered by engines that convert the energy of gasoline into mechanical energy that drives the wheels of the vehicle. This power may be applied to either front or rear axles, or to all four wheels at once. The engine burns a liquid fuel such as gasoline, liquefied petroleum gas (LPG), or electricity, producing heat and carbon monoxide in the process. Its engine is connected to a gearbox that transfers the mechanical power to the wheels. Some automobiles are also equipped with other power sources such as electric motors, batteries, hydrogen fuel cells, and water-based technologies like methanol.

The automobile is a keystone of modern society. It allows individuals to travel longer distances in relative comfort, to move more people and goods than a horse-drawn carriage or train, and to access remote locations that are inaccessible by other means. It is the most common mode of transportation worldwide. In addition, the automobile has had an enormous impact on the world economy and culture.

Invented and perfected in Germany and France toward the end of the nineteenth century by Gottlieb Daimler, Karl Benz, and Nicolaus Otto, the automobile was introduced to America in 1903. By the 1920s it was a major industry, dominated by Ford, General Motors, and Chrysler. The manufacturing methods developed by Henry Ford revolutionized industrial production and brought the car within reach of middle-class Americans.

Aside from enabling suburban lifestyles, the car has had profound social effects. It enabled city dwellers to rediscover pristine countryside landscapes, and rural residents to visit urban areas. Families began vacationing together, and teenagers had more freedom to spend time with their friends. Women, who did not always have the money to travel by other means, could drive themselves to work and shopping.

In addition, the development of the automobile led to new industries and jobs for those who made the parts and sold them. Services such as gas stations and convenience stores sprang up to provide supplies for drivers. New technology was developed to increase the performance and safety of automobiles, as well as to make them more economical to operate.

The most important benefit of the automobile is its ability to transport people over long distances quickly and in comfort. This is especially true for family trips, and it can be a significant cost saver. Cars also allow people to go places that are inaccessible to public transportation, including wilderness and mountainous areas. In addition, many people have hectic schedules, and the automobile allows them to get to their destination on their own without having to worry about being late for work or meeting other obligations.