What is the difference between configuration management and version control?

Configuration management includes, but is not limited to, version control.

Configuration management is everything that you need to manage in terms of a project. This includes software, hardware, tests, documentation, release management, and more. It identifies every end-user component and tracks every proposed and approved change to it from Day 1 of the project to the day the project ends.

Version control is specifically applied to computer files. This includes documents, spreadsheets, emails, source code, and more.

Version control is necessary but not sufficient for configuration management. Version control happens in some central or distributed repository, but says nothing about where any particular version is deployed or used.

Configuration management worries about how to take what is in version control and deploy that consistently to the appropriate places, primarily QA and production, but in a large enough development operation developers as well.

For example, you may keep all of your SQL queries in version control, including your table modification scripts, but that doesn't control when those scripts are deployed to the appropriate database server and kept in sync with the deployment of any other code that relies on that database structure.

Version control is saving files and keeping different versions of them, so you can see the change over time.

Configuration management is generally referred to as an overall process of which keeps track of what version of the code is on what server, how the servers are setup (and the install scripts to do so at many places). It is how process of what happens after the code goes into source control and how gets to deployed to the servers/desktops etc.