Bessel Functions are a family of solutions to a specific type of differential equation known as Bessel's equation. They commonly arise in problems involving cylindrical or spherical symmetry, such as heat conduction, wave propagation, and vibrations. These functions are named after the mathematician Friedrich Bessel, who studied them in the 19th century. There are two main types of Bessel Functions: Bessel Functions of the first kind and Bessel Functions of the second kind. The first kind is finite at the origin, while the second kind has a singularity there. Both types are essential in various fields, including physics, engineering, and applied mathematics.