In XWiki, everything is historized and saved under Version Control.

History View

See View the History of a Page.
See History Tab.

Major and Minor Versions

See Major and Minor Versions.
See Minor Edits.

Actions for Admins

See Delete Page Versions from History.

Comparing Versions

See Compare Versions of a Page.

Raw Changes

The raw changes between two page versions highlights the differences between page properties (title, content, parent, syntax, etc.), attachments, objects and class properties. Depending on the changes you have made you will get a result similar to this:

"Changes for page" as they appear using the Flamingo Skin 

Note that the comparison starts with a Summary that groups the changes in 4 categories: Page Properties, Attachments, Objects and Class Properties. A category is displayed only if there are related changes. Except for 'Page properties', the rest of the categories can be expanded to see which items have been added, deleted or modified. Each item provides a link to the details that are listed below the Summary.

The comparison details lists all the items (page properties, attachments, objects, class properties) that have been added, deleted or modified. For each item you can see what properties have been modified and the exact modifications. For text attachments you can even see the changes made to the attachment content between two versions of the attachment. The changes made to the object properties of type Password and Email are obfuscated for privacy reasons.

Rendered Changes

You can view how the page has changed visually from one version to another. The changes are computed on the rendered page content. The parts of the content that have not been modified are hidden by default but you can click on each ellipsis to view more context or you can use the "Show context" button to view the entire page content.

Similar to the behavior when viewing a previous version of a page, the content of previous versions is executed in a "restricted" mode that might lead to errors and other differences.

Show next/previous changes

You can change the versions directly while comparing two page versions, using the arrows depicted in the image below.

By clicking on the leftmost arrow, you will see the previous change made before the "From" version. For example, if the current comparison is between revision 4.1 and 6.1, clicking the left arrow would compare revisions 3.1 and 4.1 (assuming there are no minor versions). Similarly, the next change will be displayed by clicking the rightmost arrow (e.g. clicking the right arrow while comparing revision 3.1 and 5.1 will lead to 5.1 and 6.1 comparison). You can also use the arrows around a version to increase or decrease the associated version number.

Viewing Previous Versions

By clicking on a version from the Version column of a page's History tab you will be able to view that page's content, as it was in the selected version:

In this view, most actions on the page will actually affect the latest version of the page. However, the following actions (under the "More Actions" menu) will target the current version of the page you are viewing:

• Export
• Print Preview
• View Source

Blame View

When viewing the source of a page (by going to More Actions > View Source on a page), you can enable the blame view by clicking on Show last authors button. In this mode, each line of the page's content is annotated with the last author that modified it and the revision in which this modification was introduced. The blame view also works when viewing the source of a page revision (other than the latest one) so it can be accessed at any point in the history of a page.

Hovering the avatar and the revision number will display the author's name and the date and time when the line was changed. Multiple lines can be grouped to express the fact that they were all modified within the same revision (by the same author and at the same time).

Clicking on the revision number will display the changes view, with all the modifications performed in that particular change by its author.

At this point, if you still have not found the change you were looking for related to a particular line of content, you could continue the search by clicking on the parent (left) version, opening the blame view for it and repeating the cycle. This way you can drill down the history and focus on the content and find out, for example, when exactly was a line added, in which context and by whom.