I use the term “Business Logic” when I talk about the code that decides what is now true when an event has happened. I real-time audio software it would be the

I use the term “Business Logic” when I talk about the code that decides what is now true when an event has happened. I real-time audio software it would be the logic that decides which sample to play next and what the (say) audio volume should be now. The non-logic code is the code that read events from the environment (user input) and changes the environment (the audio hardware).