Conversations, maybe a bit confusing, but on closer inspection correct.
On other websites this is called "private messages".
But on OKiTALK, the private messaging system is a bit different, a little bit extended.
OKiTALK's messaging system can also be used to discuss with several people, exchange views, group work, etc., in private, not in public.
These messages only see members added as attendees.
That's the big difference between normal private messages.
That's why the system calls itself conversations
Here is a little video about it:
Sorry, the video itself is in German, but still easy to see how to handle it.