Answer:
Onomatopoeia is the formation of words based on the sounds they are made of.
Metaphor is the use of one word too refer to another completely different thing.
Step-by-step explanation:
Onomatopoeia is the formation of words according to the sounds they are taken from. It is an imitation of the sound produced to make a word. For example, cuckoo, hissing, sizzling, splashing, gurgle, mumble etc.
Metaphor is the literary figure of speech where one word is used to describe or talk about another completely different word. It may sometimes be used to show the similarity or difference of the words talked about. For example, he is a shining star. It doesn't mean he's a shining star. or, the speech was the calm before the storm, meaning the disaster is coming after the speech.
These two figures of speech are used often in literary works by writers to basically enhance their works and also to make them more appealing to the readers. They help in making the content more enticing, making a more creative approach to the reading.