A fire alarm is a safety device designed to detect smoke, heat, or flames in a building. When it senses a potential fire, it emits a loud sound or visual signal to alert occupants. Fire alarms can be standalone units or part of a larger fire detection system, which may include sprinklers and emergency lighting. Regular maintenance and testing are essential to ensure they function properly. There are two main types of fire alarms: ionization and photoelectric. Ionization alarms are more responsive to flaming fires, while photoelectric alarms are better at detecting smoldering fires. Many experts recommend using both types for comprehensive fire safety.