Using one object to symbolize another is known as a metaphor. One of my favorite lines from the poem "Queen of the Cats" describes how the cat's eyes would literally "spark with firelight fantasies" as she gazed into the flames.
Because the cat's imagination is represented by the firelight, this is a metaphor. Poets may employ metaphors to help their readers envision their work in a new manner. Firelight serves as a metaphor in this poem for the cat's eyes, which seem bright and full of imagination.
