TITLE: What is the difference between the Discrete Fourier Transform and the Fast Fourier Transform?
QUESTION [32 upvotes]: Can anybody answer this question?
Thank you.

REPLY [2 votes]: DFT is a discrete version of FT whereas FFT is a faster version of the DFT algorithm.DFT established a relationship between the time domain and frequency domain representation whereas FFT is an implementation of DFT.
computing complexity of DFT is O(M^2) whereas FFT has M(log M) where M is a data size