Once a rule condition is met, an action is triggered and the stakeholders are alerted. These alerts are listed in the Activity tab. Here you can see for each alert, rule name, success or failure in sending the alert message, action chosen for the rule, matches found for the rule etc.
You can search for alerts using search tokens, select a period to view the rules triggered during that time frame, click a bar to jump to the alerts triggered in a certain time frame, use filters listed on left to group the alerts by rule name, action name, etc.