Panels pages vs Entity pages (that are output using Panels)

This will explain what entities are: http://drupal.org/node/1261744

Panels can control pages that are used to display entities, i.e. node pages, taxonomy term pages, user pages, etc.

A "Panels page" is any page managed via Panels which is not for an entity page.

Metatag integrates with the entities system to control configuration, e.g. to control the default meta tags used for node pages, to allow for per-node changes, etc. Metatag's integration with Panels only goes as far as displaying the meta tags that are defined for an entity, it doesn't show the meta tag fields on the Panels settings pages.

Does that help clear up the distinction?

(moving this back to the metatag issue queue)

Just want to add: Panels doesn't natively do either of these things. "Panels pages" really means "Page Manager page configured to use Panels" and a panels entity would be a normal entity using Panelizer to render the entity via Panels.