Atype of nonfiction which explains a particular subject is called

Which detail from "to build a fire" best supports the idea that most of the real yukon prospectors had little experience for surviving in cold weather? it happened. it was his own fault or, rather, his mistake. he should not have built the fire under the spruce tree. there was the fire, snapping and crackling and promising life with every dancing flame. he would have to build a fire and dry out his footgear. this was imperative at that low temperature—he knew that much. the flame he got by touching a match to a small shred of birch bark that he took from his pocket.

In a short story the narrator's word choice

What is the author purpose for including this portion of how to eat an live cream cone