Different kinds of magical liquids are grouped in the category of potions: brews made from enchanted herbs, water from magical fountains or sacred springs, and oils that are applied to a creature or an object. Most potions consist of one ounce of liquid.
Potions are consumable magic items. Drinking a potion or administering it to another character requires an action. Applying an oil might take longer, as specified in its description. Once used, a potion takes effect immediately, and it is used up.