Simile
According to a WordNet search, it is "a figure of speech that expresses a resemblance between things of different kinds. (usually formed with 'like' or 'as')" It is used for comparison.
Similes in Poetry
Similes are used by Poets to compare things all of the time. For example:
"O my Luve's like a red, red rose, That's newly sprung in June: O my Luve's like the melodie, That's sweetly play'd in tune."-Robert Burns
Similes in Famous Songs
Madonna is internationally known as a sex symbol that likes to frequently push the envelope and reinvent herself. What most people do not realize, is that two of her biggest songs are similes.
Like A Virgin
"Like a virgin, Touched for the very first time, Like a virgin, When your heart beats, Next to mine"-Madonna
Like A Prayer
"When you call my name, it's like a little prayer, I'm down on my knees, I wanna take you there, In the midnight hour I can feel your power, Just like a prayer you know I'll take you there"-Madonna