Epsilon is the fifth letter of the Greek alphabet, represented by the symbol Ε in uppercase and ε in lowercase. In mathematics and science, it often denotes a small positive quantity or a margin of error. Epsilon is also used in various fields, such as computer science and physics, to represent limits or tolerances in calculations. In addition to its mathematical significance, Epsilon is associated with the concept of Epsilon-Delta in calculus, which is fundamental for defining limits. The term is also used in the context of Epsilon-Nets in computational geometry, which are used to approximate sets in high-dimensional spaces.