Take a reel of Moon and a reel of Guetermann polyester and look at the two side by side under a magnifying glass.
I'm pretty sure you will see lots of tiny fibres sticking out from the Moon, but far fewer sticking out from the Guetermann. It's those tiny fibres which cause a lot of the lint which collects in the crevices of your sewing machine.
Moon is also a bit thicker.
@Lowena - Moon is poly, so you can't really compare it to Aurifil, compare that to other cottons - Guetermann or SUperior Threads.