Version history records how work changes over time. It can help identify when a mistake appeared and recover an earlier state. Useful history includes a clear explanation of the change, not just a timestamp. Save meaningful checkpoints and describe their purpose. A change such as “correct the total calculation for empty rows” is easier to review than “update file.” When several people collaborate, coordinate how changes are combined and resolve conflicting edits deliberately. A previous version may contain outdated assumptions, so restoring it can undo good changes as well as bad ones. Compare before replacing. Version history also differs from a backup: a backup protects a copy under a separate recovery arrangement, while history tracks changes within a workflow. Practice: Write three clear change descriptions for a document revision. Explain which version you would use to investigate a newly discovered error and why.