Lets say an Android smartphone has been setup with multiple users. On boot up,

1. Does only the user selected (say, with entry of PIN etc) become "active" or do ALL the users become "active"? In my case, I want to activate only one selected user, kind of like user login on a desktop computer. This way, startup apps of ALL users are not running and consuming resources for no reason.

2. When active as the first selected user, and if I want to switch to another user, is there anyway to "logout" of the first user, again, just like on a desktop computer? The intention is to release resources and then "login" as another user.

3. Since last boot up, if two users have logged in (without "logging out", assuming there is a way to do it), do notifications from apps of both users show up on the lock-screen? How do notifications work when there are multiple users on the Android device?