Crafting!
Crafting is the process of turning component items (such as crafting materials) into equipment or consumables. In Guild Wars 2, there are eight different crafting disciplines, only two of which can be active at a time. Advancement in a discipline is designed to match the player's progression through the game, allowing players to create items useful to their current level without being forced to also craft unnecessary items to do so.
Crafted items look differently but always have comparable statistics to those obtained through other methods, e.g. via loot or vendors.
Crafting Wiki
-Ray