Levinson's Theorem is a concept in the field of mathematics, particularly in the study of differential equations. It provides a way to relate the solutions of a certain type of linear differential equation to the properties of its associated boundary value problem. This theorem is particularly useful in understanding how solutions behave under different conditions. The theorem is named after Norbert Levinson, who contributed significantly to the theory of differential equations. By establishing connections between solutions and boundary conditions, Levinson's Theorem helps mathematicians and scientists analyze complex systems in various applications, including physics and engineering.