Suppose there is a part of program that does not deal with initialisation, input, output. It just specifies what should be done, what is allowed or not. I use the term Business logic for this. But application can have nothing to do with business.Example: a game. Suppose there are following parts:  Input processingCollision detection, physics, player controlRendering the outputAI - How do NPCs attain the specified goal.Business logic - what happens when player touch certain objects. What types of NPCs are there and what they do when ..., concepts of lives, ammo, levels, score.But it is not business, it's just a game. Wikipedia is not clear about it.
Should I use Business logic term when speaking about non-business application?
terminology;business logic
If you're feeling weird about it or you're getting push back from others, try using the term Domain Logic instead.