Revisions allow you to track changes made to a dataset. When content is edited, Drupal will retain a copy of the current version, and create a new version alongside it. Over time, you might end up with many different versions of the same dataset, each reflecting a previous variant. While all of these different copies are stored in the database, only one of them is the one that’s used when you navigate to the dataset in your browser.

When implementing DRAFT states, it is possible to create a revision that is newer than the currently published revision. This is called a pending revision.