Playback flow of control

[John Minson]

I have the following setup

HIFICast on phone

music on a minidlna server

playback device is a Denon AVR

Within HIFICast I select the minidlna server as my music source.

I then select the Denon as the play back device

When I select a song and hit play , what happens ? I know this is not a simple question. I'm just looking for a high level explanation of the 'flow of control' between the 3 devices .

Thanks