A simile is a figure of speech that compares two different things using the words "like" or "as." This comparison helps to create vivid imagery and make descriptions more relatable. For example, saying "as brave as a lion" compares someone's courage to that of a lion, enhancing the reader's understanding of the person's bravery. Similes are commonly used in literature, poetry, and everyday language. They can add depth and emotion to writing by connecting unfamiliar concepts to familiar experiences. For instance, saying "her smile was like sunshine" evokes warmth and happiness, making the description more impactful and engaging for the reader.