What are the uses of ellipses in essays? [closed]

I’m wondering about how ellipses are used in essays. Are there any examples that I could see?

There are two types of ellipsis (examples from The Cambridge Guide to English Usage):

1. Ellipsis in the grammar of a sentence

   They took glasses from the bar and [they took] plates from the tables.

2. Ellipsis in punctuation

   He wanted no more of it . . . But having said that . . .

When I quote a long passage I might elide some irrelevant parts, and in their place I put ellipses.

For example,

When I quote a long passage, like when I quote from an old email or when I quote from a taxation bill to illustrate a nuanced legal point, I might elide some irrelevant parts, and in their place I put ellipses.

becomes

When I quote a long passage ... I might elide some irrelevant parts, and in their place I put ellipses.