What is the term for comparing two unlike things using "like" or "as"?

The term for comparing two unlike things using "like" or "as" is a simile. Similes are a common literary device that create vivid imagery and help to convey emotions or concepts by drawing parallels between disparate ideas. For example, saying "Her smile was like sunshine" illustrates a comparison that evokes warmth and positivity, enhancing the reader's understanding of the subject being described.

In contrast, a metaphor directly states that one thing is another, rather than merely comparing them; it does not use "like" or "as." Personification attributes human characteristics to non-human entities, creating relatability and depth. An analogy, while it does involve comparisons, typically explains a more complex relationship and often extends beyond a simple comparison, helping to clarify an idea through a more detailed parallel.

Thus, the unique characteristic of using "like" or "as" makes simile the correct term for this type of comparison.