Omega (capital: Ω, lowercase: ω; Greek ὦ, later ὦ μέγα, Modern Greek ωμέγα) is the 24th and final letter in the Greek alphabet. In the Greek numeric system/Isopsephy (Gematria), it has a value of 800. The word literally means "great O" (ō mega, mega meaning "great"), as opposed to Ο ο omicron, which means "little O" (o mikron, micron meaning "little").In phonetic terms, the Ancient Greek Ω is a long open-mid o [ɔː], comparable to the vowel of English raw. In Modern Greek, Ω represents the mid back rounded vowel /o̞/, the same sound as omicron. The letter omega is transcribed ō or simply o.
As the final letter in the Greek alphabet, omega is often used to denote the last, the end, or the ultimate limit of a set, in contrast to alpha, the first letter of the Greek alphabet; see Alpha and Omega.