The second is Omega (uppercase Omega, lowercase Omega, Chinese transliteration: Omega, Omega, omega, Amiga, omega). Physics: angular velocity symbol, resistance ohm chemistry: solute mass fraction, etc. There is also a watch brand called Omega.
In the Greek alphabet, the first letter is "α, α" alpha, which stands for beginning; The last letter is "ω, ω" ω, which means the end.