An apartment house is a type of residential building that typically has multiple units or apartments for people to live in. Other synonyms for the term include apartment complex, apartment building, flats, and multi-unit dwelling. An apartment complex may feature various amenities such as a pool, gym, or laundry room. Flats typically refer to individual living spaces within an apartment house, whereas a multi-unit dwelling can also include duplexes, triplexes, and fourplexes. It is important to note that different regions and countries may use different terms to describe similar types of dwellings. Overall, the term apartment house is a widely recognized synonym for this type of residential building.