SEEMs like the outline path effect doesn't do anything, but I'm sure I just need to be educated. What is the difference between them and why would I use one over the other? Thanks.
It doesn't (visibly) do anything on its own, but it modifies subsequent effects so that they act as if the stroke has been outlined -- as long as it's above them in the appearance panel.
Okay. So when would I want to use one over the other?
In any situation where you want an object to display as if it has an outlined stroke without actually modifying the path.
A simple example: both shapes have 'Roughen' applied, but the right one also has 'Outline Stroke'. It acts as if the ellipse is a compound path rather than a single stroked path, roughening the outer and inner rings separately.
AH. thank you. Will need to play with this a bit. Just scratching the surface of Illustrator's capabilities.
Thanks for reaching out. In addition to what Doug has explained, please check out this help article(https://helpx.adobe.com/in/illustrator/using/painting-fills-strokes.html) to know more about fills & strokes. Hope it helps.