Smoke detector senses smoke, typically as an indicator of fire. It's a crucial component of home and building safety systems. When smoke is detected, these devices emit a loud alarm to alert occupants, giving them time to evacuate and for emergency responders to intervene if necessary. There are different types of smoke detectors, including ionization and photoelectric detectors, each with its own method of detecting smoke particles in the air. Many modern smoke detectors are interconnected, so if one alarm is triggered, all alarms in the system will sound, enhancing safety across the entire property. Regular maintenance, such as testing and replacing batteries as needed, is important to ensure smoke detectors function properly when needed most.