A Rollback level user has the ability to use the rollback feature, quickly changing the article back to the version before the most recent user edited it. Sysops also have this ability.
A list of user's with Rollback status can be found here.
A Sysop has a number of administrative powers.
- The ability to delete pages. (Pages can still be undeleted and viewed by other Sysops)
- The ability to delete images. (Images can still be undeleted and viewed by other Sysops)
- The ability to protect and unprotect pages so that they can be edited by all users, registered users only, or Sysops only.
- The ability to ban users and ip's.
- The ability to edit pages in the MediaWiki namespace (Otherwise known as System Messages)
- The ability to revert edits using the rollback button on a diff page or user's contributions page.
A list of user's with Sysop status can be found here.
A Bureaucrat has the ability to promote other users to Sysop and additionally Bureaucrat status if chosen. They can also give a user the ability to use rollback.
A list of user's with Bureaucrat status can be found here.