Physical origin of induction and dispersion energies

Question

I am reading this book on non-covalent interactions. Chapter 1 states that there are 3 types of non-covalent interactions:

1. Electrostatic interactions, which are just the coulomb interactions between two static charge distributions. (either repulsive or attractive)
2. Induction effects that arise from the distortion of a particular molecule in response to the electric field of its neighbors. (always attractive)
3. Dispersion interactions, which are due to the correlation of the motion of electrons in different molecules. (always attractive)

The chapter uses perturbation theory. I am not very familiar with it, but intuitively it does make sense. The perturbation of the Hamiltonian due to the second molecule is given by (15) (but I imagine that one could generalize the treatment to another part of the same molecule, if one was interested in intramolecular interactions for big molecules, rather than intermolecular interactions . . . right?):

So the electrostatic interaction comes out by evaluating the expectation value of $H'$ with respect to $\Psi_{00}^{AB}$, which is just the product of the ground state wave functions of the individual molecules. The second-order terms, instead, are obtained by "mixed" states, where one or both the molecules are not in their ground state:

which is split into:

My question has to do with induction and dispersion. From the subscripts of (1.7,1.8,1.9) it seems that these are the mathematical representations of the description I gave above using only words. That is, induction terms are the ones where I'm considering a molecule in its ground state, and the other in an excited state. Dispersion terms instead have to do with the "mixing" of states in which both molecules are excited. It's not entirely clear to me to what extent this is true, and to what extent we are just applying arbitrary categorization to quantum effects. In particular for the induction term: it seems that (1.7,1.8) is allowing each molecule to deviate from its ground state wave function/density (the focus is always DFT) only in the context of its interaction with the other molecule . . . shouldn't induction have to do with the effect that electrons on A feel due to the ground-state density of B?

The other thing that confuses me is the nomenclature usually adopted here. I have always heard using the word "dispersion", and never "induction", to describe the corrections one has to implement in DFT to account for long-range intermolecular interactions (such as the D3 correction by Grimme). Other chapters of the same book do the same, and always talk about "dispersion". But given what I wrote above it would seem to me that corrections should include both induction and dispersion . . . I can't imagine any way of differentiating the two, by the way. So when we are only talking about "dispersion", is it just for brevity, or am I missing something? (According to the equations above, both dispersion and induction are after all just the second-order corrections to the energy, so essentially they are the same thing . . . )