Euler's Constant, denoted as γ (gamma), is a mathematical constant approximately equal to 0.57721. It arises in various areas of mathematics, particularly in number theory and analysis. γ is defined as the limiting difference between the harmonic series and the natural logarithm, specifically as the limit of the difference between the sum of the first n natural numbers and the logarithm of n as n approaches infinity. This constant is named after the Swiss mathematician Leonhard Euler, who made significant contributions to mathematics in the 18th century. Euler's Constant appears in several mathematical contexts, including integrals, series, and the study of prime numbers, making it an important concept in advanced mathematics.