Eleven subspecies of the White Wagtail (Motacilla alba) are currently recognised and they all have slightly different plumages.
This is Motacilla alba alba, the nominate subspecies of the White Wagtail which occurs on the European continent and migrates down as far as Kenya.

1st, 2nd & 3rd photo: Orheiul Vechi Cultural-Natural Reserve, Moldova, 29 April 2026
4th & 5th photo: Prut River area, Lower Prut Nature Reserve, Moldova, 25 April 2026