what is a fourier transform and what is it used for
What is a Fourier Series used for? Answer Wiki. The Fourier Transform is used to convert a continuous, periodic time domain signal, into the relative, instantaneous energy contained in the signal, across the entire frequency spectrum, and for *every* moment in time. This is what we call the frequency domain representation of that signal we started with.
The Fourier transform is called the frequency domain representation of the original signal. The term Fourier transform refers to both the frequency domain representation and the mathematical operation that associates the frequency domain representation to a function of time.