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 type works differently; for example, water cools the fire, while dry chemicals can smother flames and prevent re-ignition. These agents are categorized based on the type of fire they are effective against, such as Class A for ordinary combustibles, Class B for flammable liquids, and Class C for electrical fires. Proper selection of an extinguishing agent is crucial for effective fire suppression and safety.