Usage of whereby


I would like to know the usage of whereby. where and How it is used… Is it used when we talk about arrangements or processes?

Whereby can be used instead of by means of or through which.
Learning a language is a process whereby new vocabulary and grammar structures are acquired.[YSaerTTEW443543]

TOEIC listening, photographs: A stork nest[YSaerTTEW443543]