Every time a page is published, a revision is created so you can review or revert your changes if the need arises. All revisions are stored for a maximum of 180 days. In addition to revisions, you can save your work and finish editing at a later time using drafts.
To view revisions and drafts of the current page select the Edit button, and choosing View Revisions from the drop-down menu. This will open the View Revisions dialog.
To recall a revision or a drafts, select the the date that the draft or a revision was created. The draft or revision will be displayed in the Live Editor. It will not be published until you select Publish.