Is there a difference between the FFT and PSD of a signal?

[frank_davis]

Hi everyone,
I have a very basic question here.
Is there a difference between the FFT and PSD of a signal?
If so, what is the difference and which one should be used to look at the partials of a musical note?

Thanks.

 

[gowthamn]

psd fft

PSD of signal is computed as square of FFT of given signal.
U should use PSD in case if u are doing some analysis or filtering the signal.

 

[ring0]

fft to psd

Also, power spectral density is used for random processes, where conventional Fourier transform can't be applied.