Keeping track of changes is a critical functionality in every configuration management system because there are legal requirements like SOX (Sarbanes-Oxley Act) that require it. It can be accomplished in several ways. Basically you can either use an existing tool like a VCS (version control system) or have something custom-built.
When possible, I tend to prefer a VCS because it is (hopefully) already part of your process and governance approach. A typical workflow is that the underlying assets (i.e. configuration files) will be changed and then the VCS client be used to commit the change. The commit message allows to record the intent here, which is the critical information.
But there are cases when you need to be able to track things outside the VCS. In all cases I have seen so far the reason was that some information should not be maintained within the VCS for security or operational reasons. While organizations are often relaxed about data like host names in non-PROD environments, this changes abruptly when PROD comes into play. While I always think “security by obscurity” when I have that discussion, it is also a fight not worth having.
The other reason is operational procedures. The operations team often has a well-established approach that maintains configuration files for many applications in a unified way. The latter typically involves a dedicated location on network storage where configuration data sit. Ideally, there should also be a generic mechanism to track changes here. A dedicated VCS is of course a good option, but operations staff without a development background often (rightly) shy away from that route.
So it comes down to what the configuration management system itself offers. What I have implemented in WxConfig is a system where every operation that changes configuration data results in an audit event that gets persisted to disk. It includes metadata (e.g. what user initiated the change from which IP address), the actual change (e.g. file save from UI or change of value via API), and the old and new version of the affected configuration file.
The downside compared to a well-chosen commit message for VCS is that the system cannot record the intent. But on the other hand no change is lost, because no manual activity is needed. In practice this far outweighs the missing intent, at least for me. Also it has proven to be helpful during development when I had accidentally removed data. It was far easier to restore the latter from an audit record compared to looking them up in their original source.
All audit data get persisted to files and the metadata is recorded as XML. That allows automated processing, if required by e.g. a GRC system (Governance, Risk Management, and Compliance) or legal frameworks like the aforementioned Sarbanes-Oxley Act.