Hmm well I don't invent this idea / term. So i can't really define , i just follow what people called it.
Usually Negative is Exhaust more than Intake , while Positive is Intake more than Exhaust
But i have a Carbide 400R , im able to set up 10 fans in total.
I have 2X Top Exhaust , 2X Push-Pull Exhaust for my AIO Water Cooler Rad on the Rear , 1X Top Side Exhaust
4X Push-Pull Intake on Front and HDD Cage Section , 1X Bottom Intake, 1X Bottom Side Intake.
I tend to try to pull as much hot air out of my case instead of pulling in cool air.
For im in tropical country , my ambient temperature are always 30 - 33 C , rare even below 28 C , impossible to even get 26 C ( If it ever goes this low here , bad things are happening in this Earth literally )
So I find it pointless sucking more air in which will make no difference instead more and more hot air will trap and build up in my case....