The Free On-line Dictionary of Computing (30 December 2018):

Fourier transform

    A technique for expressing a waveform as a
   weighted sum of sines and cosines.

   Computers generally rely on the version known as discrete
   Fourier transform.

   Named after J. B. Joseph Fourier (1768 -- 1830).

   See also wavelet, discrete cosine transform.

   (1997-03-9)