Automatic Dry Powder fire extinguisher can be used on most fires, Class A, B and C fires (UK), flammable liquids, flammable gases and electrical fires too.
The extreme versatility and their effectiveness in extinguishing fires make them one of the most popular fire extinguishers in the home, as well as the workplace, as this video points out:
Certain types of dry powder extinguishers are specially designed for use on particular fire types, and have powders geared towards dealing most effectively with these specific situations. For instance, an extinguisher may be developed to be most effective on liquid fires or for dealing with combustible metals.
When a dry powder fire extinguisher has been used, the deposit they leave behind can be sticky and corrosive which can be particularly damaging if used on electronic/sensitive equipment, so it does require cleaning up as soon as possible (download PDF).