Answer:
Connotations are words or sentences that have an implied meaning.
Denotations are words that have the literal meaning (you can find it in a dictionary).
Bad word choice can result in a different meaning or tone in the sentence or even in the entire story! Using connotations and denotations can help your reader understand the piece of writing. Also using connotations and denotations can help your story move smoothly.
Hope this helps!