A: eZ Publish handles all content with full version control. When creating a new piece of content or updating an existing you are always working on a draft version. This is fully separate from the live content, but is available for preview in the actual templates it will be used on the site.
This enables working on new content, previewing and having approval workflows of content before it is published as live on the site.
The history of content is kept in the system and any previously published version is available for rollback at any time. You can also you the content diff functionality to visually see the difference between two content versions.