The home point is the geographic point the drone stores at take-off and returns to during Return-to-Home (RTH). It is the reference for the entire automatic return logic — if the point is wrong, the return will be wrong too.
If the point is recorded before GNSS settles, or if you carry the aircraft somewhere else after the first satellite lock, RTH will fly to the WRONG place. That is why you verify the home point on the map before every flight and re-set it whenever you move.