What does the information in parentheses impact the meaning of the text

Parentheses offset text that isn't important to the meaning of a sentence. Things like extra information, clarifications, asides, or citations. The information inside the parentheses can be as short as a number or a word, or it can be as long as a few sentences.

Explanation:

the excerpt from chapter 2 of "animal farm", by george orwell that is an example of foreshadowing is "these three (snowball, napoleon, and squealer) had elaborated old major's teachings into a complete system of thought to which they gave the name of animalism." animal farm is an allegory of how czarist russia developed into communist russia with all its corruption. old major's teachings represent marx's theories turned into communism, animalism, by the three pigs. this foreshadows the oppression and corruption that will follow this revolt.