Automobiles, also called cars, are four-wheeled vehicles designed for passenger transportation. Most are powered by an internal combustion engine that uses a volatile fuel to work; the fuel is burned inside the vehicle’s cylinders and then the pistons push down on the wheels to make it move forward. This movement is controlled by a transmission system that changes the speed of the wheels to match the engine’s output. Many different kinds of automobiles have been built for people with different needs.

Some people use their car to get to and from work; others buy an automobile so that they can visit family, travel for pleasure, and go shopping. Some people even use their automobiles to advocate for social change. In 1916, for example, two women drove around the country in their automobiles decorated with the message “votes for women.”

An automobile is an important part of modern life because it allows people to live farther from their jobs and have more choice about where they want to work and live. It is possible to drive far distances in a short amount of time, which makes it easy to travel for business or pleasure and to include more people in one’s family and social circle.

But automobiles can cause problems for society as well. Too many automobiles on the road create traffic congestion, and air pollution from their exhaust can harm people’s health. Some cities have begun to limit the number of automobiles that can be on the road, and people can use buses or trains to get where they need to go more quickly and cheaply than by car.