This is a single platform installation hosting sites belonging to different owners. Every slot is a full-fledged site with its own admin panel, not a page inside someone else's.
qwetru.ru is exactly this kind of installation, and at the same time a regional representative of the platform: you get access to the panel through a subscription with us. An organization that needs its own dedicated environment with its own access rules installs the platform on its own infrastructure — that's the Server tier, aimed at legal entities, with negotiated terms. How things work here is described on the about the server page.