Using metaphor to describe and render the characteristics of things can make things vivid and tangible, and then arouse readers' association and imagination, give people a vivid and profound impression and make the language infectious.

Describe profound truth with simple things, turn abstract into concrete, simplify complex, and help people understand deeply. And make the language vivid.

By analogy, it can make things vivid and deepen readers' impression; Used to explain the truth, it can make the truth easy to understand and easy to understand. By using it, we can turn unfamiliar things into familiar things, make abstruse truths simple, and concretize and visualize abstract things.