They're not (always) the same, a distinction can be drawn in the case if blocks of flats (and perhaps terraces, especially where council/mgmt company managed?) whereby FTTP means it's fibre to the block and copper to the flats. FTTH in such cases would afaik be pretty unusual, but hypothetically would mean that each flat has it own fibre termination.

FTTP aka FTTB (Building). The nomenclature's all a bit ridiculous IMO.