How many types of Bologneses are there?

How many types of Bologneses are there?
There is just one type of Bolognese breed, although this breed is part of the Bichon family of dogs, which includes several related breeds such as the Bichon Frise, Maltese, Havanese, and Coton de Tulear. While there are different breeds within the Bichon family, the Bolognese is a distinct and unique breed.