I can only see articles in Firefox, but not in Internet Explorer.
Pages and articles have to be published to be shown on your website. You have most likely not published the elements you are missing in Internet Explorer, and can only see them in Firefox because you are logged into the back end. While you are logged into the back end, unpublished and hidden elements are visible (extended front end preview).
Last update on 29.04.2015 by Leo Feyer.