Every time you change something in your pipeline and save it, Azure DevOps creates a new version of the pipeline:
In this tab, you can find one record for each version of your pipeline with the change type (for example, update or add), the change date, the user that made the change, and, if it exists, the comment the user left when they saved the pipeline. The topmost record is the current version.
It is a source-control system integrated into Azure DevOps for the pipeline. If you are using YAML, your pipeline will be described by a file in your source control (for example, GitHub), and this tab is used by Azure DevOps to historicize changes to the build process (for example, variables or triggers defined in the web interface).
You can use the ... menu to execute an operation over a particular version:
- Compare Difference: This allows you to check the difference between two versions.
- Revert Pipeline: This allows you to promote an old version as a new current version.