See also: Narutopedia:Sysop
Anyone can revert vandalism and bad-faith edits, but it takes a couple of clicks in the page history to get it done. Users with the "rollback" permission are able to undo bad edits with one click, by using the rollback link on diff pages, user contributions list, or the list of recent changes.
It is important to note that sysops already have rollback rights by default. Users with rollback rights are just users who are not necessarily a sysop. A list of rollback users can be found at: Special:Listusers/rollback.
On Narutopedia, rollback is a viral permission. Any user with rollback has the ability to give the rollback permission to another user. If it's used to cause trouble rollback may be removed by any sysop or bureaucrat.