The Revisions screen shows any backup copies of your post. Each time you click Save Draft orUpdate, a revision is saved. WordPress.com will store the last 25 revisions for each post on your blog. Revisions allow you to look back at the recent changes you’ve made and revert to an earlier version if necessary.
To find the Revisions screen, you will need to go to the edit screen for the post you want to see the revisions for. Then, look for the Revisions in the Publish module, and click the Browse link:
Note: This will not show until you have made some revisions. Also you can’t manually delete post revisions, but the oldest revision is automatically deleted if there are more than 25 revisions.
To view your Revisions, slide the bar at the top or use the “Previous” and “Next” buttons. The changes will be highlighted in green (for additions) and red (for deletions):
By default, when you view a given revision, it will show a comparison with the revision immediately previous to it. If you’d like to compare it with a different revision (for example, if you’d like to compare the original draft with the most recent revision), check the box by “Compare any two revisions” at the top:
To restore a previous version of a post, scroll to the desired revision, then click on the blue Restore This Revision button:
Who can see revisions?
All administrators and editors on your blog can see all post revisions. Authors can see post revisions for any post they have authored (which are the only posts they’re able to view in the Dashboard). Contributors cannot see revisions.