Automobiles, also called motor vehicles or cars, are a class of road vehicle that is designed to carry people and/or cargo. They typically run primarily on roads, have four wheels, and seat one to eight people. Although many different designs of automobiles exist, most of them use an internal combustion engine to produce mechanical energy that is converted to propel the car forward. They can be powered by steam, electricity, gasoline or another fuel. The first modern automobiles were created in the late 1800s. Many inventors, including Karl Benz of Germany and Henry Ford of the United States, developed their own designs and improved the manufacturing processes for making cars. These improvements allowed for the manufacture of mass-produced automobiles, which in turn made them more affordable to middle class Americans.

The advent of the automobile revolutionized life in America and other parts of the world. It enabled people to travel greater distances more quickly and easily, and it stimulated the growth of new industries and services such as service stations, motels and restaurants. It ended rural isolation, bringing urban amenities such as schools and medical care to rural areas. It also spawned the development of modern cities with their surrounding suburbs, industrial and residential districts.

There are a variety of special automobiles designed for specific purposes such as construction, emergency and military applications. Some automobiles are built to transport cargo such as a truck or bus. Others are designed to carry passengers such as a taxi or limousine. There are even automobiles designed to look cool like a sports car or an SUV. Regardless of the function of an automobile, they all share some common features such as a wheelbase or track, axles and a body.

During the early years of the 20th century, automobiles were the dominant form of transportation in the United States. As a result, the auto industry grew rapidly. Companies such as Ford, General Motors and Chrysler dominated the market. This was despite the fact that there were very few reliable automobiles available.

In the 1990s, the popularity of automobiles began to wane, and many consumers started to choose alternatives such as bicycles or public transit. In 2010, only 27 percent of Americans owned a car. However, many Americans continue to drive automobiles because they need to get around for work and other activities. Those that do not own their own cars often rent them, and some use public transit or ride-sharing programs to save money on car payments.

The automotive industry is changing rapidly as more Americans opt to go green and reduce their dependence on fossil fuels. There are also more and more alternative fuel vehicles, such as hybrids. These vehicles combine the best of both worlds by providing superior gas mileage and performance in an attractive package. In addition to reducing emissions, these vehicles are also safer and quieter than traditional automobiles. They are not only good for the environment but also for the drivers themselves as they do not need to be focused on driving and can relax while traveling.