Hi The legally meaning is described well in upper answer. In Korean, these are divided in law. We commonly divided two case, 아파트 and 주택. 아파트 is high and many people live in there 주택 is smaller than 아파트, yeah it is commonly under the 5 floors.

Hi，you might want to use this web page for reference: https://phmkorea.com/23792 아파트: apartments in high rise buildings 연립주택: low rise buildings, about 4 levels high, the apartment floor measurements are around 660 square meters 다세대주택: low rise buildings, about 4 levels high, the apartment floor measurements are lesser than 660 square meters I am not Korean so I can't say much about the prices and other information but I hope the generic information helps!