when I am having omega 1, omega 2, omega 3. What I am saying is that all the waves between this frequency, is essentially represented by one wave; that means, energy of all the waves between this to this is equal to half A square. So, what is the energy then? Half A square for this. So, this side axis should be half A square by d omega, so that this into this (Refer Slide Time: 23:42) that is, this area gives me the energy; that is the idea. Now, you are saying that… Let me make it smaller. You make it smaller; what would happen? You would automatically end up getting a smaller amplitude at closer frequencies if I break down a signal, if I were to do Fourier analysis, if I were to do this (Refer Slide Time: 24:02). See it is very simple. If I take N to be 200, I will get smaller value of A over smaller omegas. But, if I take N to be say just 5, I will get larger value of A over larger chunks. So, I have end up getting the same graph. So, I will end up getting this graph and this is what is called energy spectrum; we call it by s omega. And, what is the unit of that? You will see it is meter square second, because it is A square by d omega and this is omega. So, this is… Now, what is the uniqueness of this representation?