alarma

Alarma is a signal or device that warns of danger or a need for action. In everyday use, it may refer to a siren, a smoke or carbon monoxide detector, a security system, or any alert that prompts a response. Alarms can be audible, visual, or tactile, and may initiate automatic alerts to people or authorities.

The term comes from the Italian all’arme, meaning “to arms,” historically used as a call to prepare for defense. In many languages, including Spanish, the word alarma reflects a similar sense of warning.

Alarm systems typically include sensors (smoke, heat, CO, motion, door/window contact), a control panel, a power source, and notification devices (sirens, lights, or network alerts). Some devices operate locally, others dispatch signals to monitoring centers or mobile devices.

Activation occurs when a sensor detects a condition exceeding a threshold. The resulting signal triggers notification devices and may trigger automatic actions such as notifying authorities, triggering safety procedures, or affecting other connected devices. Fire safety standards such as NFPA 72 and EN 54 address design, installation, and maintenance of alarm systems.

Alarms are widely used in homes, offices, factories, and public spaces. They rely on proper installation, maintenance, and user response to be effective; false alarms remain a common concern. The term is also used for alarm clocks and digital alerts in software and devices.