Give a list of the different kinds of fire trucks that exist.

How firefighting trucks and equipment are classified varies from country to country but in the United States there are a few general categories of fire trucks. Fire Engines are what most people think of when they think of a fire truck. It has a combination of hoses, ladders, and other equipment but also carries several hundred gallons of water and has a built in pump to feed that hoses from it's internal tank or from a hydrant. There are Ladder Trucks which typically have a large extending ladder on top. These may or may not carry water but also generally have a built in pump to feed water to the nozzle attached to the ladder. There are Rescue Trucks which typically have specialized equipment for unique rescue situations such as confined space, vehicle extrication, or collapsed building rescue. These typically don't carry water or pumps but there are a few jurisdictions that have Rescue Engines that blend these two. There are also Tanker trucks that carry large amounts of water to areas where there are no hydrants and they typically do not have their own pumps or hoses. They serve primarily as a water supply to other trucks.