A taxi (taxicab or cab in the United States) is a car, or other vehicle which is used for public transport. People use them to get to where they want to go. This means there are no stops in between where they get on and where they get off. Many big cities have taxis.
In most other types of public transport, such as a bus, tram, or train, the rider does not get to choose the locations where they want to get picked up or dropped off. These vehicles often take certain roads or follow a very specific route. Because of this, they usually do not stop exactly where people want to go.
Riding a taxi is a lot like having your own car, but you don't drive it. You only tell the taxi driver where you want to go and he or she will take you there. How much you pay for the ride, in most cases, depends on how far you are going from where you get on. It is common for the price for a taxi ride to be more expensive than other forms of transport.