Parallel To or Level With

We play golf as if we were standing on railway track rails that are automatically width adjustable to accommodate our various club lengths. The Driver requires the widest rails.
An associate of mine just sent me a virally popular instructional piece on ‘Training Indoors’.
He quite simply said that one needs to get the ‘Club Shaft Parallel To The Target Line or To The Body Line’ in order to improve your swing and experience more Ball Flight Success. Where we accomplish the condition of ‘Shaft Parallel’ to these lines is very important. Will this shaft be directly over the Target Line or over the Body Line’?