Automobiles are a very important means of transportation. They are used for transporting passengers and goods. Automobiles are usually powered by internal combustion engines which use a volatile fuel like petrol, diesel etc. Some cars have hybrid systems which allow them to run on electricity as well as gasoline. The automobile is a very complex technical system with thousands of component parts. It has evolved over the years to become what it is today.

The automobile embodies both the promise and the pitfalls of modernity. Its power to liberate people from the constraints of time and place has been matched by its tendency to foster new forms of inequality, alienation and societal disintegration. It stimulated participation in outdoor recreation, and spawned related industries such as service stations and roadside restaurants. It ended rural isolation and brought urban amenities-most importantly, better medical care and schools-to the countryside. Its construction of streets and highways, one of the largest items of government expenditure, helped bring suburbanization to America.

In its heyday in the first half of the twentieth century, the automobile transformed the American landscape and society. While German and French automobile manufacturers were pioneers in design, by the 1920s they had been overtaken by the American big three. The advent of Henry Ford’s revolutionary assembly line production techniques enabled mass personal “automobility,” which put the automobile within reach of middle-class families.

Modern life would be unthinkable, or at least highly inconvenient, without the automobile. It is the most important mode of transportation in the world, and it is a vital part of the economic and social fabric of many countries.

The history of the automobile began in 1870, when Karl Benz designed and built a crude two-stroke engine that ran on gasoline. He then attached it to a handcart and used it to pull himself along. In the late 1860s Siegfried Marcus developed a similar motorized handcart, this time using a four-stroke gasoline engine.

While it was not until 1904 that Ransom E. Olds perfected the one-cylinder, three-horsepower engine that made his Model T a true competitor with the Mercedes, it was an automobile all the same.

Whether the car is driven by a water-cooled, piston internal combustion engine that propels the front wheels or by a rear-engine, gasoline-fueled, electric drive system that powers all four wheels, there are some common features. Automobiles are typically constructed with steel bodies, which are often reinforced with aluminum, magnesium and composites to reduce weight and save on costs.

Modern vehicles are driven by either liquid-cooled or air-cooled, two-stroke or four-stroke, gasoline or diesel (fuel oil). A water-cooled engine is more efficient than an air-cooled one. In some vehicles the engine is carried in the front of the vehicle, over or ahead of the front axle; this arrangement distributes the weight more evenly. It is less efficient, however, than a mid-engine layout. Moreover, it is not as easy to maneuver as a rear-engine arrangement. It is also less environmentally friendly.