What is the primary purpose of a fire extinguisher?

The primary purpose of a fire extinguisher is to control or extinguish small fires. Fire extinguishers are specifically designed for immediate and targeted response to incipient stage fires, which are fires in their early stages before they become larger and more uncontrollable. By using the appropriate type of extinguisher, individuals can effectively suppress flames and prevent the fire from spreading, which can be crucial in protecting life and property in emergencies.

The other choices, while they relate to fire safety, do not capture the main function of a fire extinguisher. Alerting others of a fire is generally the role of alarms or notification systems, not extinguishers. A fire barrier's purpose is to contain fires and prevent their spread, which is a different aspect of fire safety altogether. Reducing smoke within a space may occur in certain situations, but it is not the primary purpose of extinguishers, which focus on directly addressing flames.