What is halon fire extinguisher used for?

Class A fire extinguishers - used for fires caused by "ordinary combustibles" aka paper, wood, plastic, cardboard, etc.

Class B fire extinguishers - used for fires caused by flammable liquids such as gasoline and oil.

Class C fire extinguishers - used for electrical fires

Class D fire extinguishers - used for fires caused by explosive or flammable metals (most commonly found in laboratories

Class K fire extinguishers - used for fires found in commercial kitchens