It is possible to restore an old version of a page by following the link to that version, clicking "edit" and then saving. This should be done with caution, as it means that ''all'' changes made to the page since the time of that version will be lost.
==Moved and deleted pages==
When a page is [[Help:Moving a page|moved]] (renamed), the entire edit history of the article, before and after the move, is shown. The old title becomes a [[Help:redirect|redirect]] and loses its edit history.
If instead of a move, the entire content was [[cut and paste]]d into a new substitute article, the page history gets spread across two articles. The histories can be [[Wikipedia:How to fix cut-and-paste moves|merged]] in this case.
When two pages are merged, typically one becomes a redirect. In this case the revision history of the redirect is kept.
When a page is deleted, its revision history remains in the database and can be retrieved by an administrator, who can also undelete the page (see [[Wikipedia:Viewing and restoring deleted pages]]).
Administrators can also remove selected revisions from a page history, for example if they contain defamatory text. For details, see [[Wikipedia:Selective deletion|Selective deletion]].