- 하녀 = female servant. (an old term rarely used nowadays.)
- 가정부 = hired female housekeeper. (가사 도우미 (domestic helper) seems to be more popular these days.)
하녀 has a strong sense of servitude. 가정부 has somewhat less of it but not entirely.
가사 도우미 sounds like working for someone as a paid service or some other arrangement, so it is more suitable for the modern times.