Her Sanskrit name is "Sarasvatî Devî", which means "flowing water", and so Benzaiten is the goddess of everything that flows: water, words (and knowledge, by extension), speech, eloquence, and music. The characters used initially to write her name, read "Biancaitian" in Chinese and "Bensaiten" in Japanese (辯才天), reflected her role as the goddess of eloquence. Because the Sutra of Golden Light promised protection of the state, in Japan she became a protector-deity, at first of the state and then of people.
In the end, she became one of the Seven Gods of Fortune, and the Sino-Japanese characters used to write her name changed to 弁財天 (Benzaiten), which reflects her role in bestowing monetary fortune. Sometimes she is called Benten, although this name refers to the goddess Lakshmi.
In the Rig-Veda (6.61.7) Sarasvati is credited with killing the three-headed Vritra, also known as Ahi ("snake"). This is probably one of the sources of Sarasvati/Benzaiten's close association with snakes and dragons in Japan. She is enshrined on the Island of Enoshima in Sagami Bay, about 50 kilometers south of Tokyo, and numerous other locations throughout Japan; and she and a five-headed dragon are the central figures of the Enoshima Engi, a history of the shrines on Enoshima written by the Japanese Buddhist monk Kōkei (皇慶) in AD 1047. According to Kōkei, Benzaiten is the third daughter of the dragon-king of Munetsuchi (無熱池; literally "lake without heat"), known in Sanskrit as Anavatapta, the lake lying at the center of the world according to an ancient Buddhist cosmological view.
Benzaiten has been syncretized with some Shinto goddesses.