What is a figure of speech that is an exaggeration or overstatement

What is the theme of "the story of the fisherman”?

London includes a quote about john thornton as he is observing hal attempt to motivate the exhausted dogs "it was idle, he knew, to get between a fool and his folly". if the word "idle" is defined as "of no real worth, importance, or significance", what does this statement mean with regard to hal? who is the fool? what is hal's folly? why would john thornton think it of no real worth or useless to intervene?

Why is it important to include a descriptive subject heading? it in sorting the topics. it the recipient see its importance. e-mail programs won’t allow e-mail to be sent without it. it keeps junk e-mail separate from important e-mail.