Vocabulary: mold or mould?

Tutoring English, words keep generating interest. The tutor mentions mold and mould.

Apparently, the difference between mould and mold isn’t meaning, but nationality: mould is the British spelling of the American mold. For instance, in Britain, mould can refer to a form, but can also mean a growth on bread. In America, mold is used for either.

Source:

grammarist.com