gnus terminology question: new messages vs messages seen but not read

[Alan Schmitt]

Hello,

I would like to configure something in gnus, but I don't know the
terminology so I don't know what to search for.

When I visit a mailbox, messages I've never seen have a small dot in
their status. When I quit the mailbox, these messages will lose their
dots if I visit the mailbox again even if I have not read them. There is
thus a distinction between never seen messages, and seen (but unread)
messages. When I open a mailbox, the cursor is put on the first never
seen message if there is one, and on the first unread message otherwise.
I would like the cursor to be put on the first message unread in every
case.

My questions are: what is the terminology for these "never seen before"
messages? And is there a configuration variable to choose the message on
which to focus when opening a mailbox?

Thanks a lot,

Alan