Fire extinguishing agents are substances used to put out fires by interrupting the combustion process. Common types include water, foam, dry chemical powders, carbon dioxide, and wet chemical agents. Each agent works differently; for example, water cools the fire, while dry chemicals can smother flames and prevent re-ignition. The choice of extinguishing agent depends on the type of fire. For instance, Class A fires, which involve ordinary combustibles like wood and paper, are effectively tackled with water. In contrast, Class B fires, involving flammable liquids, require foam or dry chemical agents to prevent the spread of flames.