The fifth letter of the Greek alphabet.

Epsilon (capital ε, lowercase ε) is the fifth Greek letter.

Lower case ε is used for:

Math:

Very small

The ∈ symbol indicating "belonging" in a set relation.

Levi-Civita symbol (levi-Civita symbol)

Computer science:

blank line

Accuracy of number types

Physics: Dielectric Constant of Conductor

The phonetic symbol used in American English is the e sound of bed.

The Latin letter e is changed from Epsilon.

It often represents photon energy or electric potential energy, etc.