Portable fire extinguishers are anticipated as first line of defense to cope with fires of limited size. They are needed even if the property is equipped with automatic sprinklers, water stand pipe and hose, or other fixed protection equipment. Every facility (commercial industrial, office, etc) is required to have fire extinguishers regardless of any other type of fire protection provided.
Basically, there are five different types of extinguishing agents. Most fire extinguishers display symbols to show the kind of fire on which they are to be used.