The Fast Fourier Transform or FFT is a computationally efficient way to compute the fourier transform of a real or complex function. It relies on the input data to be uniformally spaced, and excels at large numbers of points as the number of operations to complete the FFT is of order 5 N log₂ N instead of N² as with the standard Fourier transform algorithms. It is often most efficient when the input data series possesses 2^M points, where M is an integer.