Is there a fundamental difference between backups and version control? <p>How does version control differ from plain backups?</p> <p>Let's forget about the feature decoration, and concentrate on the soul of version control. Is there a clear line that backups must cross before they can be called a VCS? Or are they, at heart, the same thing with different target markets?</p> <p>If there is a fundamental difference, what is the absolute minimum requirement for something to reach the status of version control?</p> <p><em>When you answer, please don't just list features (such as delta compression, distributed/central repositories, and concurrent access solutions) that most version control systems have or should have, unless they actually are necessary for a VCS by definition.</em></p>