Water in a very fine mist from above, as only professional firefighters are able to do, will help cool the fire, but 'hosing' it will only spread the fire
foam fire extinguisher or a fire retardant spray
It will put out burning fluids.
Liquid
A carbon dioxide (CO2) fire extinguisher is best for putting out a computer fire.
A type b extinguisher puts out a class B fire, i.e., flammable/combustible liquids and gases.
Burning liquids such as gasoline, kerosene, paint, acetone, and so on.
A fire extinguisher should be used to put out a fire safely in a laboratory. It is essential to know the type of fire extinguisher suitable for the specific type of fire, such as Class A, B, or C fires, to effectively extinguish the flames.
Extinguish means "put out", so a fire extinguisher puts out fire.
a fire extinguisher can put out a fire
Well, you CAN- depending on the type of fire.
Yes. Depending on the type of fire and the type of extinguisher, you may simply spread the fire (which is bad enough) or you might actually cause more damage (trying to put out a sodium fire with a water based extinguisher, for example).
No. Depending upon the type of fire, there are other ways. For instance, a brush fire can be put out with dirt or water, but is generally put out by removing the fuel. An electrical fire might be put out by simply turning off the electricity. A fire extinguisher contains water or other chemicals and you can certainly apply water or chemicals to a fire without having them come out of an extinguisher.