A fire extinguisher is a portable device used to put out small fires. It contains a specific extinguishing agent, such as water, foam, dry powder, or carbon dioxide, which is released when the extinguisher is activated. Fire extinguishers are classified based on the type of fire they can combat, including Class A for ordinary combustibles, Class B for flammable liquids, and Class C for electrical fires. To use a fire extinguisher effectively, remember the acronym PASS: Pull the pin, Aim the nozzle, Squeeze the handle, and Sweep from side to side. Regular maintenance and inspections are essential to ensure that fire extinguishers are in working order and ready for use in emergencies.