Every save that changes an article's text keeps a version: the title, the excerpt, the text and each translation. The newest 100 are kept.
- Open the article and choose the History tab.
- Each version shows when it was saved, by whom and what it changed.
- Choose two versions to compare them. Words taken out and words added are marked.
- To bring an earlier version back, open its menu and choose Restore.
A restore is itself a new version, so nothing is lost: you can always go back to what was there before.
The "Updated" date readers see changes only when the published text does, never for a new tag or a new category.