Three, there was something once called practical magic, which is different.

第三，曾经有一种叫做实用魔法的东西，这是不同的。

Sirius and Lupin had given Harry a set of excellent books entitled Practical Defensive Magic and its Use Against the Dark Arts, which had superb, moving colour illustrations of all the counter-jinxes and hexes it described.

《实用防御魔法及其对黑魔法的克制》，里面的魔咒都有彩色动画图解。