In incident.io, there are three concepts that represent the importance of something.

In alerts and escalations, these are priorities, which allow you to configure branches in your escalation path.

When you notify someone about an escalation, that's done with an urgency, which determines how a user is notified. Users can configure separate notification settings for high and low-urgency notifications.

Lastly, once you create an incident, that has a severity. An incident's severity indicates how significant this incident is. These are kept different from alert priorities, as the way you determine incident severity may differ from the priority of a single alert.

For example, you may have an alert with an urgent priority that you want someone to look at immediately, therefore sending them a high urgency notification. However, the problem may only be impacting a small part of your application, or a single customer in an edge case, so you deem the incident severity to be minor.