# Concepts
<a name="alarm-concepts"></a>

CloudWatch alarms monitor metrics and trigger actions when thresholds are breached. Understanding how alarms evaluate data and respond to conditions is essential for effective monitoring.

**Topics**
+ [Alarm data queries](alarm-data-queries.md)
+ [Alarm evaluation](alarm-evaluation.md)
+ [PromQL alarms](alarm-promql.md)
+ [Composite alarms](alarm-combining.md)
+ [Alarm actions](alarm-actions.md)
+ [Alarm Mute Rules](alarm-mute-rules.md)
+ [Limits](alarm-limits.md)