Firefighters primarily put out fires using water. Firefighters get the water they use to fight fires from water pumps, fire hoses, aircraft carrying water and fire extinguishers.
Firefighters sometimes use chemical retardants to put out fires, depending on the type of fire and where it is located. Special fire extinguishers contain these chemical retardants. Grease fires are one type of fire that shouldn't be extinguished with water. Firefighter training involves learning what type of chemical to use on various fires.
Firefighters also fight fires using methods that prevent the fire from spreading, such as cutting fire lines to create firebreaks. This method is used in forest fires. When the fire is not able to garner more fuel from the land around it, it dies out. "Hotshots" are firefighters who have received advanced training to work specifically with forest fires. Smokejumpers are firefighters who are trained to parachute from airplanes into small forest fires and keep them from spreading.
Air support is another firefighting tool that is important in preventing extensive damage from forest fires and very large structural fires. Air tankers are capable of carrying hundreds of gallons of water or retardant, much more than a fire truck can carry. Air support also can be in the form of helicopters and other small aircraft that take firefighters to remote fires.