Outline view is excellent when you are fleshing out your script. You can write the main action that occurs and key dialogue. In outline view you will see which scenes are weak and which are ok. You will also see where you need to add more direction or more dialogue, possibly bringing in or eliminating a character.
As you write out more and more of the script, you can continue to use outline view to see how each scene works and how the scenes work together as a script.
Each paragraph has a little icon at the beginning of it showing what type of paragraph it is. Each paragraph that is collapsible has a little box to the left of the icon, optionally with a + or - in it. All the paragraphs in outline view have a left margin that is as far to the left as can be displayed based on the icon positioning. However, the paragraph width is identical to page view and therefore each paragraph breaks at the same words and is the same number of lines long as it is in page view.
Act, Scene, and Character paragraphs can be collapsed. When you collapse a paragraph, that paragraph itself stays wholly visible. But the paragraphs under it that belong to it are then hidden. When you do this the + inside the box becomes a -. (If a paragraph has no paragraphs under it, the box is empty.)
You can move text in outline view by dragging the icon to the left of a paragraph. When you drag using the icon you drag all text in that paragraph and all paragraphs belonging to it. This makes it a very easy way to move not only scenes but dialogue blocks as it moves the character, parenthetical, and dialogue.
Outline View does list pages. But they are not script pages. If you print in outline view it will fill each page and therefore the page breaks will fall differently. Outline view needs fewer pages than page view because nothing is double spaced. The page numbers given in outline view match outline pages.
However, outline view is essentially page-less - on purpose. This lets you view the script as a single continuous flow, which is how the final movie is viewed too. Whenever you want to work on your script as a single document, outline view may be your best option.