The Archive is an area that holds all old properties that are no longer active, either because they were sold or are no longer being managed by you.
Clicking on the Archived tab above the property list will allow you to see all properties that are in the Property Archive for all active companies which you have access to. The information in the archived tab is read-only. The magnifying glass can be selected to preview the summary of the property. To restore a property (to un-archive), select the rotating arrow toggle.