I'm not sure if they are all based on the same idea but most power yogas I have done move faster from one position to the next. Almost a new position for every breathe instead of holding a position once you are in it....u def raise your heart rate and sweat more. But give it a try...worst case you walk out....best case u get a good workout. Just mention to the instructor that u are a bit of a newbie so she can keep u informed of any modifications. Always modify....yoga is about YOUR practice afterall and NOT about keeping up with the super bendy pretzels in class!

It really depends on the teacher and the place I think. Power classes generally involve more dynamic, challenging and heat-generating poses and Power Flow moves those poses from one to the next, hence the flow. But some places simply call a Power class a next level up from a Hatha or Hatha Flow class. Ask your gym what they mean by it. I went to a "Power" class at a community centre once and there was not much to it. Then I joined a yoga studio and tried their Power class and got my butt kicked! But you know what? I loved it, kept going and still love it to this day:)