Thanks for the clarification! Now I have to ask, does the multiple pov mean shifting pov during or between scenes? I've always thought any shift within a single scene was headhopping.Well, I calibrate POV by scene, so single-POV means one POV in a scene. Multiple POV means more than one POV in a scene, so as you say, during scenes.
Single-POV in a scene means you can have more than one POV in a book, which is pretty much a necessity in many types of books with more than one protagonist (like romances, family sagas, and most thrillers). But many writers in more narrow-focus stories stay in one POV the whole book. It depends a whole lot on genre and type of book, how big the scope is, and how tight the focus.
Multiple-POV means that in some scenes (not necessarily all), the viewpoint shifts from one character to another (and maybe to another). That's a legitimate evolution of the omniscient POV approach, and more modern and more suited, I suspect, to our fast-paced world and especially younger readers, who are used to having nine browser windows open while texting their three best friends and doing their homework (sort of :).
But there's a danger, especially in less experienced writers (and, I think, writers who don't absorb well from their reading), that the multiple approach, uncontrolled, will devolve into headhopping.
That isn't really a danger for single-POV writers (but it is, I think, for omniscient writers).
What I suggest is decide what you do well, what you do naturally, and go with that, and do it as well as you can. But there's no doubt it's easier if your natural POV approach is single-third, because most editors feel comfortable with that.
It's a bit harder to "sell" multiple-POV, but it's so good for some stories and it comes naturally to a lot of writers. I always counsel multiple-POV writers to stay in one POV as long as it works, and then shift smoothly and clearly to the new POV and stick with that as long as it works.
If it's done smoothly, and it works, editors and readers get the benefit of the juxtaposition of viewpoints without the jarring. :)