Salvage is a trade skill and provides a means of recovering raw materials from items. When an item is salvaged, it is destroyed and some of the material used to craft that item is recovered. This is not an efficient process and so results will vary from time to time. It does however, have the benefit of allowing potential recovery of most types of material used in item crafting, so while not as efficient as specific resource gathering, it does provide some advantages through its versatility.
Salvaging an item also has a chance to give a recipe for creating the item.