{{Infobox Demo/doc}} is a version of the basic infobox structure which can be used in instructional situations to showcase two instances of the infobox side-by-side. This happens because it does not automatically {{clear}} — unlike the "real" infoboxes.
It is based on {{Infobox Object}}, so it does not include any of the navigational variables.
One page that uses this template extensively is T:GTI.