What is metaphor?
Metaphor is a comparison between two dissimilar things, or images that require the reader to picture one thing as being another.
A metaphor has two parts: the tenor or main subject of the metaphor, and the vehicle, the thing that the tenor is being compared to. In order to concoct a metaphor, the tenor and the vehicle must be dissimilar.

How is it used in poetry?
Metaphor is one of the poet’s finest tools. An original metaphor is a delight to read and stays with the reader long after the page is turned.
Human feelings such as love, pain, sorrow, hate, hunger, etc. can be difficult to describe or explain because they are abstract concepts. Using metaphor to compare abstract ideas or feelings to something concrete can make them more specific and help the reader understand and empathise.

The Road Not Taken by Robert Frost

Snake by Colin Thiele

First Autumn Morning by Kijo Murakami