Yes, in many Linux systems and environments where Vim is used as a text editor, a file with a tilde (`~`) at the end, like `config~`, typically represents a backup file. This backup file is automatically created by Vim when you edit and save changes to the original file (`config` in your case). It contains the state of the file before the most recent save.

This feature is intended to provide a simple form of version control. If you make changes to your `config` file and then realise you need to revert to the original version, you can use the `config~` file to do so. However, it's important to note that this backup only represents the state of the file before the last save, not an extensive history of changes.