The purpose of a fire alarm system may seem quite obvious, but it can often go beyond what most people would realise.
A fire alarm system is a form of active fire protection. using a network of devices throughout the building, it will monitor day and night for smoke or heat being generated, and will alert any occupants as required that there is potential danger within the building.
Your fire alarm system will have been designed to work in harmony with any passive fire protection within the building such as fire doors and compartmentation. When a fire is detected by the fire alarm, it will sound throughout the building, alerting occupants of the potential danger as well as controlling other systems such as closing fire doors, opening smoke vents and alerting the control centre so they can take the appropriate action.