Interpretation of QED in the Standard Model

[Naty1]

Three related questions on which I could use some help:

a] In another thread, Bill_k posted something like:

"Electrons, being charged, could exchange energy by exchanging a virtual photon."

ok, yet I thought electrons usually interacted via the EM field ['real' photons]...

So how do we distinguish between when virtual photon versus and real photon exchange occurs? I started reading Wikipedia to see if I could find out and decided to post here because I got confused:

b] Wikipedia in the QED introduction says

...QED mathematically describes all phenomena involving electrically charged particles interacting by means of exchange of photons and represents the quantum counterpart of classical electromagnetism giving a complete account of matter and light interaction. ...

Does this mean the exchange of virtual photons lies outside QED?

A few sentences later in Wikipedia:

c]

...In technical terms, QED can be described as a perturbation theory of the electromagnetic quantum vacuum.

Is that correct?

I thought the the Standard Model involves quantum field theory of NON-perturbative behavior; That is, where the vacuum has a non zero vacuum expectation value...For example I have read Higgs and QCD are a/w NON perturbative vacuums...QED is different??

Thanks

 

[Naty1]

Regarding my own question [c]..Wikipedia sez...

Vacuum energy is the zero-point energy of all the fields in space, which in the Standard Model includes the electromagnetic field, other gauge fields, fermionic fields, and the Higgs field.

http://en.wikipedia.org/wiki/Zero-point_energy

apparently I am more confused than I suspected!?? but they all seem to be treated on the same basis...