In childhood, magnets were one of our favorite toys. We always played with them and were amazed by their peculiar characteristics. Two magnets always have two sides that can attract each other, and two sides will always repel each other. We always split them up and down. In middle and high school, we learned from the knowledge that the compass leveraged the theory of magnetism.

Now in our lives, different magnetic materials are used in many places. So today we come to understand its characteristics.