Forms of the Fourier Transform

There are four forms of the Fourier Transform, as follows:

Fourier Series -- Transforms an infinite periodic time signal into an infinite discrete frequency spectrum.

Fourier Integral Transform -- Transforms an infinite continuous time signal into an infinite continuous frequency spectrum

Discrete Fourier Transform (DFT) -- Transforms a discrete periodic time signal into a discrete periodic frequency spectrum

Fast Fourier Transform -- A computer algorithm for calculating the DFT

They will be discussed in more detail in the next section.