>>13949286afaik:
the ampere is a unit of measurement that represents the quantity of electrons flowing past a single point in space over a certain timeframe
voltage on the other hand is always measured as a comparison between two points - it is always going to be relative and never absolute. we use the general mass of earth/"ground" to provide a somewhat static, reliable baseline that we then base all of our engineering around
so an "11,000V 3 phase supply" on overhead lines is something like 6350V phase to earth, 11,000V phase to phase potential difference. this makes sense just by looking at the sine waves and how large the physical gaps are between any of the two points you are testing between, pic rel:
