This is the 582nd most frequent Finnish word.
kotoisin
"Originating from" or "native to."
In this sentence, 'kotoisin' is used to express the origin or homeland of the subject.
Olen kotoisin Suomesta.
I am from Finland.
Here, 'kotoisin' specifies the subject's origin, emphasizing the place within a larger geographic region.
Hän on kotoisin pienestä kylästä Lapissa.
He/She is from a small village in Lapland.
In this question, 'kotoisin' is part of an inquiry about someone's place of origin or hometown.