Source : Free On-Line Dictionary of Computing

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)