The Compare page allows assessment of changes between two versions of the same item, as saved by Rollback.
Initiating a comparison
Depending on the set up of the module that contains the item being compared, you will be presented with options. Currently compare is only available on Add/Edit, Edit Specific and Structure modules.
Comparisons require an earlier and later version of the item in question. If you compare an item via the Activity page, the earlier version is the one which was edited, and the later version will be the recent amendment.
If you have a Preview URL set up then the option of a text or visual output is presented, otherwise a text output is the chosen mode.
This view shows the changes as a textual differential. With additions highlighted in green, deletions in red and everything else in grey. Fields are output as they appear in the database.
This view shows the changes directly on your site, with optional highlighting to emphasise the effect of the changes.
Visual output is only available if Preview URL is setup on the appropriate modules.