Zeta (uppercase Ζ, lowercase ζ; Greek: ζήτα, classical or zḗta, zíta) is the sixth letter of the Greek alphabet. In the system of Greek numerals, it has a value of 7. It was derived from the Phoenician letter Zayin . Letters that arose from zeta include the Roman Z and Cyrillic З.

Read more about Zeta:  Name