You can craft almost anything in Divinity: Original Sin Enhanced Edition from food, books and scrolls to potions, armors and weapons, etc. For others, Crafting can help you save a few bucks by repairing equipment, especially in the early game where money is hard to come by.
While Crafting is totally optional and may seem like too much work for some players, it is definitely worth a shot as it is very easy to do and can provide your characters with some great upgrades that may just be the deciding factor between life and death in a battle. This required object can be the finished good itself, or be an ingredient to be further used to make the required items.
Crafting in Divinity: Original Sin Enhanced Edition is done by merging two or more ingredients into the required object.