Workbook History and Version Control
Workbook History feature allows users to maintain and manage different versions of a workbook. As you upload newer versions of a workbook, previous versions are stored in the SpreadsheetWEB database. You can access the list of existing versions from the Edit Web Application page by clicking on the Version History found on the Edit Application page.
Version History page lists names, update time of each workbook, and the name of the user who did the updates. Also listed is a link to download each workbook version. You can change the active workbook to a previous version by clicking on theicon next to it.