Confused about Fourier transform output I am new to signal processing, so I did a fourier transform on a frame of 200 samples with NFFT = 512 and then I took the absolute value : 



I am trying to understand these values on the output, are these frequencies ?
I tried to plot them, here is the result : 



Does it mean that my frame contains 60khz frequencies, I am a little confused about this output.
The frequencies at FFT output are relative to the input sampling rate fs and the FFT size N. The $k^{th}$ index corresponds to a frequency $k*fs/ N$. Pay attention that values above $N/2$ correspond to negative frequencies