Been hearing a lot about this new buzzword in golf, the one plane swing but what i want to know is, is this really just the same as having a 'connected swing'?

My swing has always been based on connection where my left arm stays close to my chest and I just turn my body back and through. This means I am fairly flat but my ball contact is solid. At the range last night someone told me i had a perfect one plane swing, Ive never really understood this so is connection and one plane the same thing? And is it a good thing?