Comment by iMerNibor

From what I recall, its about phyiscal to virtual color matching, so pantone offers samples of say plastic with the exact matching color as the virtual ones, so you can pick a color, tell the manufacturer you want the plastic molded that color and be pretty sure you'll get the right color of product (or if not you can go back to them and tell them to do it according to spec).

You'd also want to calibrate your monitor accordingly of course