DefinitionFourier series and transforms are mathematical techniques used to represent and analyze functions in terms of their frequency components. Fourier series decompose a periodic function into a sum of sine and cosine cathetus, while Fourier transforms generalize the concepts to non-periodic functions representing them as integrals of complex exponentials over the entire real line. In addition, Fourier series and transforms provide information on the frequency content, amplitude, and phase of functions. Fourier series and transforms are used in areas that use varying frequencies such as signal processing, image analysis, quantum mechanics, and communication systems to view the signal, filter noise, and secure information. For example, F(k) = ∫- ∞ ∞ f(x) e-2πikx dx is the Fourier transform of the function f(x), with F(k) representing the frequency domain of the function.