Difference between duplicate(copy/paste) vs option(alt)+Drag

Command+D is different from Option+Drag. But I’m not exactly sure how they are different and when you use one over another. For instance, let’s say you have a component set consisting of three icons(Facebook, Instagram, Tiktok). Command+D => Component/Variant4 whereas Option+Drag => Component. My guess is that Command+D or Copy/Paste creates a double of the selected element whereas Option+Drag creates an instance of the main component. In some cases, they are interchangeable but in some cases, they’re not. It’s somewhat confusing.