Jacobi Elliptic Functions are a set of functions that arise in the study of elliptic integrals and are used to describe the behavior of periodic phenomena. They are defined in terms of the complex variable and are periodic in two directions, making them useful in various applications, including physics and engineering. These functions, denoted as sn, cn, and dn, are analogous to trigonometric functions but are more complex due to their dependence on two parameters: the amplitude and the elliptic modulus. They play a crucial role in solving problems related to elliptic curves and differential equations.