Relatively small dwellings containing two or more living units for people not of the same family or household, where each dwelling does not necessarily have a full range of residential facilities so that residents must share certain common areas, such as a kitchen, bathroom, and sitting room. Examples include dwellings used as temporary transitional residences. Distinguished from larger "multiple dwellings," which contain relatively complete residential units for multiple households within a single building or complex that has a smaller number of common areas, such as a laundry room.

Source: AAT

http://vocab.getty.edu/page/aat/300129542