Metaphor is a figure of speech.It refers to a comparison between unlike things without the use of "like" or "as".This comparison is done between two things that are basically different but have something in common in some significant way.It is used in reference to something that does not literally suggest a similarity.Metaphor is different from a simile or analogy because metaphor asserts that one thing is another thing and not just that they are like one another.
Thus metaphor indicates direct comparison between two or more seemingly unrelated objects.Metaphors are widely used in literature especially poetry.It is capable of expressing emotions and feelings with the usage of minimum words.There are different types of metaphors like extended metaphor,mixed metaphor,dead metaphor,conceptual metaphor etc.Metaphor is a Greek word that means transfer.It is a trope which means that it is the figurative use of an expression.A famous example of metaphor is "All the world's a stage" by Shakespeare.Some other instances are "he was wading in money","life is an ice cream" etc.