Omega is the last letter of the Greek alphabet, like Z is for English. The Greek alphabet starts with alpha and ends with omega, which is why people sometimes say “the alpha and omega” to mean everything from beginning to end, or the most important and complete version of something.

You'll see omega used as a symbol in many fields. In science and math, the lowercase omega (ω) represents different measurements and concepts, like angular velocity in physics. In astronomy, scientists use omega when discussing how the universe expands. The uppercase omega (Ω) represents electrical resistance and other mathematical concepts.

The word appears in everyday language too. When something is described as “the omega point,” it means the final destination or ultimate goal.

Because omega means “the end” or “the last,” it creates a powerful contrast with alpha, which means “the first.” The pairing of these Greek letters helps express completeness in a memorable way that a simple “A to Z” just doesn't quite capture.