According to Hesiod, Eros was one of the first beings in the universe, having been born from chaos. He is not even mentioned in Homer. An attendant of Aphrodite, Eros is the personification of sexual desire, a force older and more powerful than even the gods. He is also said to be the most handsome of the gods.
In later mythology, there are several variations as to the origins of Eros. Aristophanes writes that he was born of Erebus and Nyx. The most common version, however, is that Eros is the son of Aphrodite and Ares. In these later versions, Eros is portrayed as somewhat mischievous, causing both the gods and humans grief.
The Romans name for Eros, Cupid (in Latin, cupido - desire) is more commonly used today.
Aristophanes. The Birds.