Often overlooked and taken for granted, taxicabs are a kind of single passenger or small group public transport. Taxis act as vehicles for hire, and transport people between locations of their choice for a fee. Unlike buses and trains, the passenger determines the pick up and drop off points, not the driver. There are four major kinds of taxicab, though they may not be called by these names, depending on location.

Hail a hackney carriage and get to where you need to be. Private hire vehicles are also available, and may be called minicabs. Private hire taxis are available only by pre-booking - you can't hire them on the street. Jitneys, or taxibuses, are a type of bus/taxicab hybrid that operate on preset routes like a bus. Limousines are also a kind of taxi, but are usually only available by pre-booking.

The customs and standards pertaining to taxi vary from country to country, and sometimes from city to city. The first hackney carriages started operating in the early seventeenth century in London and Paris. The first service we can document was started by a man called Nicolas Sauvage in Paris, and dates from 1640s. His vehicles were called fiacres, since the major vehicle depot in the city was near a shrine to St. Fiacre. In French, this term is still used to describe horse drawn carriages for hire. The Hackney Carriage Act was passed in London in 1635 and was the first legislated control on vehicles for hire in English. Eventually hansom cabs replaced older vehicles due to being faster and safer.

A major advance in taxi services was the taximeter. This device, originally mechanical but now often electronic, calculates the fare in the cab. The first modern taxicab equipped with a meter was the Daimler Victoria, built in 1897. Gas powered taxicabs started operating in Paris in 1899, in 1903 in London, and in 1907 in New York. During the twentieth century, taxicabs became more and more common, partially due to the integration of two way radios into them in the 1940s. This worked more efficiently than the previous callbox method. In the 1980s, computer aided dispatching came into being, and was a significant innovation.

Cabbies are expected to have a strong knowledge of all the places their customers may wish to go. However, as time goes on and technology advances, more and more taxicab companies are beginning to use GPS tracking in their vehicles. This augments the traditional printed map included in most taxicabs. Poorer countries generally still rely on the driver's memory and the map, since GPS is not always available. Despite the availability of this technology, some areas that have the option of using GPS tracking do not make use of it. London's black cab taxis, for instance, still rely on strict training of their drivers instead. Minicabs, on the other hand, are making use of this technology much more frequently.