Sprouting differences between seed,bean and nuts?

I am confused, pine nuts are called nuts but are a seed. If they sprout does that mean they are seeds? I have been sprouting beans, mung etc. and seeds, sunflower, broccli etc. but have never tried nuts. Found sprouted pine nuts under the trees. Does anyone know where I can fine pine nuts to sprout? They seem to be such a localized item. Thank you for any help.