Atkinson's Theorem is a result in the field of mathematics, specifically in the area of functional analysis. It provides conditions under which a certain type of sequence of functions converges uniformly. This theorem is particularly useful in the study of Fourier series and other series expansions, as it helps to establish the convergence properties of these mathematical constructs. The theorem is named after the mathematician Atkinson, who contributed to the understanding of function spaces and their properties. By applying Atkinson's Theorem, mathematicians can better analyze the behavior of sequences of functions, leading to more robust conclusions in various mathematical applications.