However, while talking about PWM, I often keep getting confused about some theoretical aspects of the same...!! And so am posting a few of my 'confusions' here to seek answers from experts...!!

There few things to a PWM which I would like to know about:

1) Its own 'frequency' (I am not sure if I understand this one. Is there one...?? If there is one, what or how is it)

2) The freq of modulation: The frequency with which, the width of the pulse changes (This is understood fairly well but not in combination with 1) above)

3) Since, PWM has a 'freq', can a 1kHz pure sine wave, for instance, be compared with 1kHz PWM...?? I mean, freq of a sine wave, is loosely defined as the number of times the sine wave repeats itself every second...!! How would the corresponding definition for PWM would look like?

4) Since PWM is not a pure sinusoid, can a PWM be deconstructed as sums of sines and cosines of ever increasing frequencies...??

Thanks in adv and Regards

Rahul