alert

Alert is a term used to describe a warning or notification designed to draw attention to potential danger or important information. As a verb, to alert means to warn someone or to cause someone to become aware of something. As a noun, an alert is a warning signal, message, or state of vigilance that prompts a response.

Etymology: The word derives from Old French alerte meaning watchfulness or wakefulness; it entered English in the early modern period. The sense of a prompt to act developed with the widening use of alerts in technology and medicine.

Emergency and safety alerts include weather alerts, amber alerts for missing children, silver alerts for missing seniors, and public safety alerts issued by authorities. Modern systems include Wireless Emergency Alerts and the Emergency Alert System that broadcast to mobile devices or broadcast media. These alerts typically specify the action to take and the scope or duration.

In computing, an alert is a user interface component that draws attention to an event, such as an error, a confirmation request, or a notification. Programming languages may provide alert functions or dialog boxes. Alerts can be passive (log entries) or active (interrupt workflows).

In everyday cognition, alertness refers to sustained attention and readiness to respond, influenced by sleep, health, and workload. Organizations use alerting practices to monitor systems, security, and health data, often routing alerts to responders based on severity and context.

See also: alerting, notification, warning, alert box, emergency alert system.