The Fourier transform is a mathematical function that can be used to find the base frequencies that make up a signal or wave. For example, if a chord is played, the sound wave of the chord can be fed into a Fourier transform to find the notes that the chord is made from. The output of a Fourier transform is sometimes called a frequency spectrum or distribution, because it displays a spectrum of the frequencies of the input. This function has many uses in cryptography, oceanography, machine learning, radiology, quantum physics as well as sound design and visualization.