We are all still feeling this out, but here is what I believe to be correct right now.
-
Yes, the only thing that is really new in Portals is the Branding Section in settings. Everything works the same as it did last week. Portals is primarily a marketing repackaging, or maybe a new way of looking at things, for now but I believe that new market will trigger other changes going forward.
-
Yes, you control access to apps via user/group permissions. You can have more than one portal as the portal is sort of defined by the Workspace homepage in your Permission Group's Additional tab. Add a new group to assign other users to and you get a new portal. To control access to data, there are a couple of techniques. One is to have a where clause in every applicable query that filters by their own records. I use this technique myself. You do need a way to link the Retool account to their client_id. I have a write up on how I do that here: How to get retool user id? - #2 by bradlymathews. the other is to use Row Level Security in your database. That is more complicated, but more hands off once you get it set up, and you still need to link the client_id to the Retool account.
While I was writing this @antonybello posted some clarifications here: Introducing Retool Portals and Retool Embed - #8 by antonybello