A simile's defining feature is that it figuratively compares one thing, person, place, element or idea to another while using the words "as", "such as" and "like." The only figure of speech that is similar to similes is metaphors because they also use comparison to make the writing more colorful and memorable, but metaphors do not use the words "like", "as" and "such as" like similes do.
An example of a simile: She's like a summer breeze.
An example of a metaphor: She's a summer breeze.