1.  Ōmega is the twenty-fourth and final letter in the Greek alphabet. Its alphabetical name literally means "great O," as opposed to omīkron which means "little o."

2.  Ōmega is sometimes 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. When both alpha and ōmega are used to represent a set, the combination represents totality as in "I am the ALPHA and OMEGA says the Lord God, who is and who was and who is to come, the Almighty" (Revelation 1:8).

3.  Ōmega's phoneme is always pronounced long and sounds like the "o" as in "note." Its corresponding short vowel is omīkron.

4.  Ōmega's lower case letter is easily confused with the English letter "w." It may be helpful to remember that the Greek alphabet does not have a corresponding letter to the English letter "w."

5.  Ōmega is transliterated into English as "Ō" or "ō." The macron marking above the letter differentiates it from the short vowel omīkron.