Question

What is an outline ?

Answer 1

An outline is a general description of that's gives the essential features but not so much as the specific details

hope this helps

Answer 2

An outline is the structure or skeleton of a paper, essay, book, etc.
An outline contains the paragraphs and the topics included.
For an example,
"Why I like dogs better than cats" (title of the essay)
1. Dogs are better than cats (the main idea of the paragraph)
   A. Dogs are friendlier
   B. Dogs are cute  (both of these are "topics" that will be discussed in the paragraph)