In ancient Rome, thermae (from Greek thermos, "hot") and balnea (Greek βαλανείον, balaneion) were facilities for bathing. Thermae usually refers to the large imperial bath complexes, while balneae were smaller-scale facilities, public or private, that existed in great numbers throughout Rome.
Most Roman cities had at least one, if not many, such buildings, which were centers not only for bathing, but socializing. Roman bath-houses were also provided for private villas, town houses, and forts. They were supplied with water from an adjacent river or stream, or more normally, by an aqueduct. The water could be heated from a log fire before being channeled into the hot bathing rooms. The design of baths is discussed by Vitruvius in De Architectura.
Thermae, balneae, balineae, balneum and balineum are all commonly translated as "bath" or "baths". Later usage of the terms loses the distinctions made by earlier authors.