"The Version History screen allows you to manage prior versions of the item being edited.
Each time you save the item with new changes, a new version is created automatically."
Source: Joomla! Documentation.
Default Version History Settings
Version History is enabled by default for the following kinds of item:
- Articles & Categories,
- Banners & Banner Clients,
- Newsfeeds, and
- User Notes.
Version History is NOT enabled by default, but can be enabled for the following items:
To enable or disable the Version History component, select the OPTIONS button at the top of the relevant screen of your website's Control Panel.
And then the relevant tab, which will vary by item type (example, Articles).
How to review the Version History
You can review and select previous versions of items after signing into the Front End or Control Panel.