A large red vehicle blares its siren, honks its horn, and speeds toward the location of a reported fire. As the other cars on the road pull over to move out of the way, you might wonder if the red vehicle is a fire engine or a fire truck. Although most people use the terms interchangeably, a fire engine is actually different than a fire truck.

A fire engine is typically the first vehicle that arrives at the scene of a large fire. It helps firefighters fight the flames with water and chemical flame-retardants. Fire engines usually have a pump, a water tank, and hundreds to thousands of feet of powerful hoses. The water tank contains hundreds of gallons of water and serves as the firefighters’ H2O source until they can connect to a fire hydrant (or other external water source). Fire engines also carry nozzles and other tools that are needed for the hoses.

A fire truck, on the other hand, is a vehicle that transports firefighters and their equipment—ladders, rescue gear, and power tools—from the fire station to the fire. Rather than carry water, fire trucks are auxiliary vehicles that carry tools such as ground and aerial ladders. Some of these ladders extend upward from the truck, using the vehicle as a base. Some fire engines may also carry ladders, but you’ll find the majority of firefighters’ ladders on their trucks.

Depending on the situation, firefighters who arrive on a fire truck focus less on directly fighting the flames and more on supportive tasks such as roof ventilation, monitoring the fire’s movement, and rescuing any victims. Because fires can be highly unpredictable, fire trucks contain ample emergency equipment that firefighters can use if the fire spreads quickly, an explosion occurs, or if people are trapped in a collapsed building. Chainsaws, fans, extra protective gear, breathing masks, and strong lights can all help firefighters do their jobs. Firefighters on the truck, then, coordinate with their coworkers on the fire engine to efficiently extinguish the fire and prevent loss of life.

So the next time you spot a fire department vehicle heading to an emergency, you’ll hopefully have a better sense of which type of vehicle—fire engine or fire truck—you’re seeing.