Alerts allow you to learn about problems in your systems moments after they occur. Robust and actionable alerts help you identify and resolve issues quickly, minimizing disruption to your services.
Grafana alerting is enabled by default for new OSS installations. For older installations, it is still an [opt-in]({{< relref "./unified-alerting/opt-in.md" >}}) feature.
- Alerting rule - Evaluation criteria that determine whether an alert will fire. It consists of one or more queries and expressions, a condition, the frequency of evaluation, and optionally, the duration over which the condition is met.
- Contact point - Channel for sending notifications when the conditions of an alerting rule are met.
- Notification policy - Set of matching and grouping criteria used to determine where and how frequently to send notifications.
For information on how to create and manage Grafana alerts and notifications, refer to [Overview of Grafana alerts]({{< relref "../alerting/unified-alerting/_index.md" >}}) and [Create and manage Grafana alerting rules]({{< relref "./unified-alerting/alerting-rules/_index.md" >}}).
