That diagram seems to show both a neutral and a ground. Both exist in the UK? Don't they use a delta configuration for most of EU to save copper? Are both supplied by the sub-station?
Yes. Neutral and ground are separate.
No. Delta is not used at low voltage. The final service voltage is 230/400V wye. In Uk, most residential is single phase 100A @ 230V. Large residences and small commercial premises will usually have 3 phase 100A @ 230/400V.
Whether both neutral and ground are supplied by the sub-station depends on the type of service and cabling.
TN-S (separate earth supplied by substation), TN-C-S (combined neutral/earth supplied by substation, with redundant earthing in transit and separated at point of service drop) and TT (no earth connection provided by substation, customer provides earth rod at service entrance) are all common.
Thanks for quality answer! The diagram had 3 phases and residential appliances and thus I naively wondered if those epic 100 amps in the UK were supplied by 3 phases to every home.