Eta (uppercase Η, lowercase η) Greek: ἦτα) is the seventh letter of the Greek alphabet. Originally denoting a consonant /h/, its sound value in the classical Attic dialect of Ancient Greek was a long vowel, raised to in medieval Greek, a process known as iotacism.
In the system of Greek numerals it has a value of 8. It was derived from the Phoenician letter heth . Letters that arose from Eta include the Latin H and the Cyrillic letter И.