What is the literary technique Langston Hughes uses in his poem "Harlem"?

One central literary technique, also called a literary device, in Langston Hughes's poem "Harlem" is simile. A simile is a type of figurative language in which an author creates further meaning by drawing a comparison between two things by saying that something is like something else. The comparison is usually drawn by using the words like or as.

In "Harlem," Hughes uses multiple similes to explore what happens to a "dream deferred," meaning a dream delayed from being fulfilled. He creates most of his similes using images of death and destruction. For example, his first simile compares a dream unfulfilled to a dried up raisin, which is a grape that is no longer alive on the vine and devoid of all of its life-sustaining moisture. In still another simile, he compares an unfulfilled dream to a sore that has become infected, and infections can lead to serious health problems, even death. Other similes compare the dream to "rotten meat," "sugar," and a "heavy load."