Automobiles are one of the most universal of modern technologies, a major industry with more than 73 million new vehicles in operation worldwide. An automobile is a motor vehicle designed for passenger transportation on land and fueled most often by gasoline (also called petrol in some countries). The term “automobile” comes from the Greek words for self-propelled and mobile. A car’s design has to balance the needs of many different factors, including cost-effective manufacturing, comfort, safety, and visual appeal.

Automobiles have revolutionized the way people live and work. They have transformed whole societies around the world by allowing individuals to travel long distances quickly and to move goods and services to market more effectively. However, they also have created new problems such as pollution, traffic congestion and the sprawling development of low-density urban areas that degrade landscapes. They have given individual owners a powerful sense of freedom of movement but have left society without clear guidelines on how to use that freedom responsibly.

Modern automobiles are complex machines with thousands of parts that have to function together to make them run and operate. Like the human body, they are composed of several semi-independent systems. Each system serves a specific purpose. The engine is the heart of the automobile, producing the power that drives the wheels and provides electricity for lights and other uses. The transmission is the link that delivers that power to the wheels. And the cooling and lubrication systems keep the engine running cool and smooth.

Thousands of different types of automobiles exist today, ranging from small and inexpensive to expensive and luxurious. Those that are designed for the mass market include sedans (or saloons in British English) and station wagons, which have four doors and usually a trunk. Coupes (American English) are two-door models that are generally considered sportier than sedans. SUVs (sport utility vehicles) are rugged automobiles that combine the towing capacity of trucks with the passenger-carrying capacities of sedans.

Many other types of automobiles are designed for special purposes, such as racing cars, luxury sports vehicles, and commercial and military vehicles. Automobiles are also used for taxi service, delivery and pickup services, police and fire fighting, and other public and private uses. They are an important part of the economy, providing millions of jobs in factories and at gas stations, restaurants, motels, and other businesses that serve them. But they also create many problems, such as accidents and air pollution, which kill millions of people each year. In addition, they cause congestion in cities and take up valuable parking space. As a result, many people have started to consider alternatives to owning and driving automobiles. For example, some have begun to ride bicycles. Others have switched to ride-sharing programs, where they share their personal automobiles with other passengers. In some cases, these programs have become more popular than owning and operating their own automobiles.