A form of market structure studied by economists is monopoly. when is a firm aâ monopoly, or are monopolies only theoretical concepts that do notâ exist?

A monopoly is when one corporation controls every aspect of the production say of a metal right from digging it out of the ground to putting it on the shelf for sale. With rampant globalisation it may be that a true monopoly is harder to find now but I believe that some companies or groups of companies still control the production, manufacturing and sale of some of the world's products.