A taxicab is like a big car that you can ride around in, just like when Mom or Dad drives you to school or to the store. But instead of being driven by your mom or dad, it's driven by someone called a "taxi driver."
You can usually call a taxi driver to come pick you up, or you can find them waiting on the side of the road with a special sign on the top that says "taxi." You can usually tell if a car is a taxi because it has a special paint job or sign on it that says it's a taxi.
When you ride in a taxi, you have to pay the driver for the ride. This payment is called a "fare." The fare is usually based on how far you are going, how long it takes to get there, and whether it's a busy time of day or not.
The driver will usually have a meter or some kind of device that helps them calculate how much the fare will be. When you get to your destination, you give the driver the fare, and they will give you change if you need it.
Taxicabs are a very convenient way to get around, especially if you don't have a car or don't want to drive. They are usually available in big cities or busy areas, but it's important to always be safe and only get into a taxi that you know is safe and trustworthy.