A kind of comparison. That is to endow people with the characteristics of certain natural objects (animals, plants, minerals, etc.), visualize the language of poetry, and make the emotions expressed by poets more intense. For example: "I am already a crazy ocean, / but she is the calm moonlight! / She is obviously in my heart, / but hanging high in the sky. / I keep reaching out to grab it, / but it only gives rise to some sadness The pursuer "I" and the pursued "she" are compared to the "ocean" and "moonlight" in nature respectively, making the symbolic meaning of the poem vivid, appropriate and more expressive.