A report snapshot is report output captured at a point in time that contains all report formatting information and full results. Report snapshots are run on a predetermined schedule, in essence allowing a report history to be created over time. Snapshots are rendered in a final viewing format such as HTML when an application or user requests them. This setting is configured on a per-report basis: Navigate to Report Manager, select Report Properties, and then select Report History. Refer to http://msdn.microsoft.com/en-us/library/ms156291.aspx for additional information.