Greek Capital Letter Epsilon

U+0395

\Epsilon

The capital Greek letter (capital epsilon) is visually very similar to the upper-case Latin letter E. For that reason, refer to the usage of Capital E for how the symbol appears in math.

Greek Small Letter Epsilon | Symbol

The ε (epsilon) symbol is a Greek letter used in math as a variable to represent error bounds and in calculus to represent the epsilon-delta definition of limits.