Steer the handle around a sideways swing plane
The speaker compares the handle to a steering wheel, the clubface to a car, and the swing plane to a road. The golfer's job in this model is to steer the club around the body and back to the ball on a sideways angle.
Channel: stayhandsy
Watch official source at 5:36Why this context matters
The speakers refer to their swing plane as 'the 45.'