The automobile is a self-propelled passenger vehicle that uses four to eight tires and is powered by an internal combustion engine or electric motor. Automobiles are a major source of transportation for people & goods. The branches of engineering that deal with the manufacture & technology of these vehicles are called Automotive Engineering.
Although the modern automobile is a complex machine, its basic systems have only changed slightly over time. A typical car contains thousands of individual parts, arranged into several semi-independent systems with specialized functions. For example, like the human body, the automobile has a circulatory system for coolant, for lubricating oil, and for fuel. It also has a system for delivering air to the engine so that it can run smoothly and quietly.
In the late 1900s and early 1920s automobile production increased rapidly as manufacturers developed efficient manufacturing techniques, particularly the assembly line. The automobile was an important force for change in America, allowing people to reach jobs and other places in a very short period of time. It opened up new opportunities for work and personal freedom, enabling women to drive on their own and to carry campaign signs for votes for women.
The automobile also stimulated a number of ancillary industries, such as steel and petroleum and gasoline, which developed to provide the raw materials needed for car manufacture. However, the growth of these industries brought with it a number of social problems. For example, automobiles promote sprawl (i.e., straggling, low-density urban development) which degrades the landscape and produces traffic congestion that can immobilize the cars themselves.