Is there a fundamental difference between backups and version control?

Question

How does version control differ from plain backups?

Let\'s forget about the feature decoration, and concentrate on the soul of version control. Is there a clear line

Answer 1

In my opinion, here are some minimum features of a VCS which may not be in a basic backup:

1. A VCS should store more than one versions (where as a backup might store only the latest last-known-good)

2. Because of 1., each version should be identified somehow (date, tag, version ID)

3. A VCS can typically support more than one concurrent user

4. A VCS for source code will normally have support for branching, merging, adding comments, and viewing deltas

Answer 2

There's certainly a grey area between them, however I would define as follows:

Version control is triggered by a 'write' action, where as backup is generally triggered by a time interval.

Backup software can be configured to run every second, and not store data if no changes have occurred, but that's not enough for it to be considered version control in my eyes, since it is possible for a file to change twice in a second.

Answer 3

Version control keeps a history of changed, and most version control systems only store the difference between two versions, not everything. Backups store everything, and they have no history unless you do it manually. Backups are inefficient usually. However version control systems are not very efficient with binaries.

Answer 4

Version control is basically an automated backup system that allows multiple users to contribute. There are absolutely more features involved with software like CVS, but yeah, it's a backup system under the hood. That doesn't mean you should manually backup instead of use version control, though, they're just in the same niche of computing.

Answer 5

The capability to perform branching and merging separates version control systems from plain backups. "Multiple concurrent universes".

See also Eric Sink's excellent version/source control guide.