Similes are comparisons between two objects using the words "like" or "as" and are generally pretty easy to identify because of the presence of these words. In describing part of a field, Wroblewski uses a simile thus: "The area was an interesting mix: the logged-off parts were ugly as sin. . . ."
Metaphors can be a bit more difficult to identify because they involve the comparison of two generally disparate objects, but without any signal words such as "like" or "as". Further complicating matters of the metaphor is the special kind of metaphor known as personification, which assigns human characteristics to non-human things. One example that is fairly easy to identify occurs in Henry Wadsworth Longfellow's "The Sound of the Sea", where in the opening line, the sea is given the characteristics of a person: "The sea awoke at midnight from its sleep. . . ." In The Story of Edgar Sawtelle, a description of a mysterious secret is explained using personification in these lines: ". . .she understood the house was keeping a secret from her", and "It was clear that the bed positively knew the secret".
Similes, metaphors and other types of figurative language provide a way for writers to create imagery and even drama in the minds of the readers; the idea is not simply to state the idea, but rather to illustrate it, capture the reader's imagination, and draw the reader in. Figurative language is a tool that authors use as they strive to tell their story in a way that is more artistic and less straightforward.