This is a comparison of two unlike things using the terms "like" or "as".
this is a direct comparison of two things, in which they are said to be (in some sense) the same thing.
this is the reference to a person, place, or event from history, literature, or religion with which a reader is likely to be familiar.
this is extreme exaggeration used in a literary work.
this goes beyond the literal meanings of words to create special effects or feelings.
this is a phrase in common use that can not be understood by literal or ordinary meanings.
this is something which seemingly cannot be, yet it is; a contradiction.