Hi Vittal,
I think you are asking about the All report access user group? That group would give a user access to every report in the company account.
Virtual Report Suite is like a segment applied on a report suite level so you will get restricted data only in your reports. Here is more on that - https://marketing.adobe.com/resources/help/en_US/reference/virtual-report-suites.html
Rollup Report suite is a combination of multiple report suites and displays summarized data. Here is the documentation on that - https://marketing.adobe.com/resources/help/en_US/reference/rollup_report_suite.html
Let me know if you have more questions. Thanks!
Tanmay