Veins and deposits are protrusions of minerals (gems, ore, and stone) found around Azeroth and Outland, in caves, and almost always in mines that can mined if you have the Mining profession and a mining pick. On the surface, they tend to appear on the edges or around rocky ridges, but may appear almost anywhere, even under water. "Node" was another word for veins and deposits during the Wrath of the Lich King beta, but was later changed. Players also use the term node to generically refer to any object that can be harvested.