Understanding the _definst_ folder, I need clarification please

Question

Hello all,
I understand with FMIS that we place our media files inside the _definst_ folder which is located in another folder (for example, one called 'streams') which is located in the applicaitons folder (Path: .../applications/streams/_definst_ )
Do I understand correctly that _definst_ can be named with any name as opposed to _definst_?
And if this is true, then all I have to do to ensure the video is located is to specify the actual name of the folder (for example: .../applications/streams/motorcycles )?
UPDATED:
I think I was reading things wrong. In going through Tom Green's tutorial I think I gained more understanding. Please let me know if this is more correct.
The _definst_ folder would be located in this path: .../applications/streams/motorcycles/_definst_
the thought being that the streams folder contains any number of other folders, /motorcycles, /boats, /cars, whatever, and in each of those folders goes a _definst_ folder into which the appropriate media is placed?
I am learning and wanted to make sure I understood this correctly.
Many thanks in advance!
Sincerely,
wordman

Answer 1

_definst_ is primarily used when you don't give your application connection an instance name. So:
rtmp://111.111.111.111/myApplication will connect to the _definst_ (default instance) instance.
Whereas if you use:
rtmp://111.111.111.111/myApplication/superVideo_v1 will connect to the superVideo_1 instance.
Why would you care? because you can separate out your users to instances. Like rooms in a chat app or something like that. Maybe  you have a set of videos and you want to separate your users out to "paying" and "nonpaying" or something. Then put lower res videos in the non paying folder:
install dir of FMS/applications/myApplication/streams/nonpaying
and
install dir of FMS/applications/myApplication/streams/paying
Kind of thing. There's a whole slew of tutorials here to check out if you haven't seen them yet: http://www.fmsguru.com/tutorials.cfm