On the Alert Analysis dashboard, you can see alerts for the active devices. Active devices are devices that generated an Expel alert within the selected time period. After you first open this tab, you see active devices for the last 30 days, but you can specify a different time period using the list on the upper right.
Using the list on the right, you can sort the alerts in different ways.
Depending on the device and the area you click, you see information about Expel alerts or vendor alerts.
Some areas also have links to more information in Workbench.