What is the purpose of a smoke detector?

A smoke detector serves a critical function in fire safety by detecting smoke in the environment and alerting occupants to the presence of a fire. When smoke is present, the detector's sensors trigger an alarm, which provides an early warning that can be crucial for safely evacuating a building. This early detection is vital as it allows occupants to respond quickly, potentially saving lives and reducing property damage.

The other options do not align with the primary purpose of a smoke detector. For example, providing light during a fire is not a function of smoke detectors; they are designed solely for smoke detection rather than providing illumination. Monitoring temperature levels is also not the role of smoke detectors, as their focus is on identifying smoke particles rather than temperature changes. Lastly, while some fire safety equipment is designed to extinguish small fires, smoke detectors do not have the capability to put out fires; their role is purely to alert people to danger so that responsive actions can be taken.