boundary conditions
 

can someone give an explanation about boundary conditions in SU2. Im a novice in CFD

what I know from a simple simulation is to say put an object in middle and make an inflow and outflow domain around that.

but for example in QuickStart config file (and many others) I dont see any inflow outflow.
it is just the airfoil and farfield??

how the software knows the direction of the flow?

any help would be appreciated