system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why exactly do aircraft need to bank when they need to turn?

Why exactly do aircraft that wish to turn left- or right-wards need to bank? I understand that it's necessary, but not really very keen on the why.

(Also, am I correct in assuming that banking in space would be needless/pointless, and that shows and films showing spacecraft doing that are wrong?)

Thanks.
gpt
banking the aircraft changes the direction of lift and angles it towards the direction of the turn. In effect, the wings now push the plane in the direction of the turn, rather than simply hold the plane up. However you do lose lift, and for long or particularly steep banks you have to apply power and yaw to keep the nose level.

You can turn the aircraft using yaw (rudder) only. But you risk stalls and spin of you do it too sharply.