I have a set of data I'm trying to analyse. It's a time series of number of objects, and it follows the general trend of increasing with time. Although I've not observed a reduction at any time step this is still possible by the definition of the system (objects are added and taken away, just the addition is significantly more likely and typically an order of magnitude greater than a subtraction). I've looked into time series analysis and Wikipedia says they can either be analysed in the frequency domain or the time domain, the the frequency domain page lists:
Fourier transform – nonrepetitive signals, transients
Which sounds like my sort of data. Now what I'm interested in is why sort of result might I get from applying an FFT to a time series like I've described above? I don't understand what the frequencies would actually mean. So I understand that if I was analysing speech then it would show me the specific frequencies of sound, but what are the frequencies of discrete counts like this?