1. Track Changes Over Time with Historical Trend ReportingHistorical trend reporting uses a special custom report type designed to highlightchanges between five snapshot dates, such as five business days or five business weeks. You canvisually represent the data changes in charts and on dashboards.
2. Report on Historical Data with Reporting Snapshots A reporting snapshot lets you report on historical data. Authorized users can save tabular or summary report results to fields on a custom object, then map those fields to corresponding fields on a target object. They can then schedule when to run the report to load the custom object's fields with the report's data. Reporting snapshots enable you to work with report data similarly to how you work with other records in Salesforce.