What is the difference between 3rd person omniscient and 3rd person limited pov?

What sound device is used in the following excerpt from how the animals lost their tails and got them back traveling from philadelphia to medicine hat by carl sandburg

Read the excerpt from "death by black hole."albert einstein's general theory of relativity, published in 1916, provides the insight to understand the bizarre structureof space and time in a high-gravity environment. later research by the american physicist john a. wheeler, and others, to formulate a vocabulary as well as the mathematical tools to describe and predict what a black hole will do toits surroundings.read the excerpt from "man listening to disc."and i bow deeply to thelonious monkfor figuring out a wayto motorize or whatever-his huge pianoso he could be with us today.these excerpts are similar because both texts

Was chris mccandless a hero why or why not