Not exactly, FFT tells you two things:Dante wrote:If you then sent the resulting timbre (non sine) then FFT analysis would tell you what the two sine frequencies are !
SO - FFT takes a complex waveform and breaks it down into the component sine wave frequencies that are making that timbre !
1. how to reconstruct the waveform with frequency components determined by the FFT settings
2. how much the frequency "bins" resonate with the signal (amount of energy expressed at those frequencies)
Notice how the spectrum analyser behaves with sine waves, it does not just give you a single line to represent the sine, because of how fft works (you can get a line with specific frequencies, but there are very few of those).
And then you have the inverse FFT (ifft), which does the opposite and transforms frequency components into a waveform.