To me “FEEL” is the amount of pressure to use at any given time depending on the situation.
Feel is knowing how to stimulate a horse without over reacting, it is an acquired art!
Feel is knowing how far you should go on any particular day.
Feel is knowing if your horse is balanced or is he heavy on his front end. Is he driving from the hind end or just pulling himself along. Example of feel being applied (copy paste into your web browser: https://youtu.be/UyJ-aSIrFHc