Mansion' can be a low-rise, mid-to-high-rise, high-rise or even superhigh-rise apartment housing, without no distinction by the number of stories, but as a general understanding, the general term 'mansion' refers to a mid-to-high-rise or high-rise building constructed for dwelling.
マンションには低層住宅、中高層住宅、高層住宅、もしくは超高層住宅があり、階数による区別はないが、一般的な概念としては中高層住宅、高層住宅の住宅用途の建物をマンションと呼ぶ場合が多い。