What a crafting component is for in The Witcher 3
Crafting components in The Witcher 3 are the raw materials Geralt hands a blacksmith or armorer: ore and ingots, hides and leather, plates, and the parts cut from monsters. Every component lists what it is used to craft, what dismantles down into it, and the merchants who stock it.
Most Witcher 3 components are themselves made from something simpler. Ore becomes an ingot, an ingot becomes a plate, and each step costs a crafting fee, so the chain is worth following before buying anything at the top of it.
Dismantling and buying components in The Witcher 3
Dismantling is usually cheaper than buying. Swords and armor picked up on the road break down into the plates and leather a Witcher 3 diagram asks for, and every component page lists the items that dismantle into it.
The other side of the same relationship is on the Witcher 3 crafting diagrams page, which shows what a given recipe consumes rather than what a material produces.