Hi Satyakam,
A reporting snapshot is mainly for creating 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.
Thanks