From Wikigogy

Rollback is a spam fighting tool. Generally use Revert meathod, not rollback, to revert a page to a previous version unless you are fighting rampant spam.

Only Admins can use rollback. Be aware that rollback reverts potentially many separate edits because it reverts all the way back to the latest version by someone other than the last person to edit the page.

To do a rollback, an Admin clicks rollback on a page's diff page. This rolls the page all the way back to the latest version by someone other than its latest contributor, not back to the older diff!

Revert meathod is better for careful revisions. Rollback is a spam fighting tool.