Wiki article on this topic:
A chauffeur is a person employed to drive a passenger motor vehicle, especially a luxury vehicle such as a large sedan or limousine. A woman employed to drive a passenger motor vehicle is a chauffeuse.
Originally, such drivers were often personal employees of the vehicle owner, but now in many cases specialist chauffeur service companies or individual drivers provide both driver and vehicle for hire, although there are service companies that just provide the driver.
The term chauffeur comes from the French term for stoker because the earliest automobiles, like their railroad and sea vessel counterparts, were steam-powered and required the driver to stoke the engine. Early petrol/gasoline-powered motor cars, before the advent of electric ignition, were ignited by 'hot tubes' in the cylinder head which had to be pre-heated before the engine would start. Hence the term chauffeur which, in this context, means something like "heater-upper". The chauffeur would prime the hot tubes at the start of a journey, after which the natural compression cycle of the engine would keep them at the correct temperature. The chauffeur also maintained the car, including routine maintenance and cleaning, and had to be a skilled mechanic to deal with breakdowns and tyre punctures en route, which were very common in the earliest years of the automobile.
Only the very wealthy could afford the first automobiles, and they generally employed chauffeurs rather than driving themselves. A 1906 article in The New York Times reported that "...the chauffeur problem to-day is one of the most serious that the automobilist has to deal with.", and complained that "...young men of no particular ability, who have been earning from $10 to $12 a week, are suddenly elevated to salaried positions paying from $25 to $50..." and recommended the re-training of existing coach drivers.
While the term may refer to anybody who drives for a living, it usually implies a driver of an elegant passenger vehicle such as a horse-drawn carriage, luxury sedan, motor coach, or especially a limousine; those who operate buses or non-passenger vehicles are generally referred to as "drivers". In some countries, particularly developing nations where a ready supply of labor ensures that even the middle classes can afford domestic staff and among the wealthy, the chauffeur may simply be called the "driver".