Major Dravidian languages include
Tamil,
Malayalam,
Kannada, and
Telugu. Although almost all of them are in the south of
India, with Tamil also in northern Sri Lanka, there is one called
Brahui in
Iran, which is believed to be the last vestige of a much wider geographical spread, before the
Indo-European-speaking
Aryans invaded from the north. (But see
Aryan invasion theory for a questioning of this traditional archaeological view.)
It is possible that the undeciphered ancient language on the seals of the Harappan civilization was also Dravidian; this would fit the above spread, but there is no direct evidence for it.
Phonologically they are remarkable for distinguishing dental and alveolar T, N, and L, as well as retroflex. (The alveolar series has been lost in Tamil of Tamil Nadu.) It is likely that Sanskrit adopted the retroflex series from Dravidian. Words or at least names are often strikingly polysyllabic.
In recent years it has been tentatively established that the language of ancient Elam, just to the east of Sumer at the head of the Persian Gulf, is distantly related, and the larger family may be referred to as Elamo-Dravidian. Its wider affinities are unknown but it is often included in the Nostratic hypothesis, linking it with many of the other families of Eurasia.
Tamil separatists in Sri Lanka uses the name Eelam (or Ilam) for their homeland; I presume this is just a coincidence.