We would like to archive Approved expense reports after certain period.

I checked in some posts from years ago in this community and it was mentioned that the only way to archive approved reports was to reject  and afterwards archive the reports. We find this solution/process not suitable for our organization as we would like to keep the reports with the latest REAL status (Approved or Rejected) available either in the tool or externally.

Having said that I would like to understand what does it mean to Archive an expense report. There is a button to archive and a view in Reports to see archived reports, but are those the actual reports? Or is it a lighter version of the report? What is the benefit of archiving a report? Does it make the other views (All, Approved, Rejected, etc.) lighter?