A fire alarm is a safety device designed to detect smoke or heat and alert people to the presence of a fire. It typically consists of a sensor, an alarm sound, and sometimes a visual indicator. When smoke or heat is detected, the alarm activates, warning occupants to evacuate the building and seek safety. Fire alarms can be found in homes, offices, and public buildings. They are often connected to a central monitoring system that can notify emergency services, such as fire departments, in case of a fire. Regular maintenance and testing are essential to ensure they function properly when needed.