I don't really understand your picture, but:
- intake = a fan that brings air from outside the case.
- exhaust = a fan that pushes air out of the case.
So, generally, you want an intake in the lower front of the case and an exhaust at the upper back.
This way, the "cold" air gets inside the case from the front, passes around the components, and the "warm" air leaves the case through the back.
The side intake is usually there for more air to the CPU and GPU area. Some cases have a duct mounted there. Also, some "warm" air is pushed out by the power supply.