Difference between second sidebar and different styled widgets?

As a WP novice, I’m confused about the vernacular here on the forum between a second “sidebar” and widgets styled differently within ONE sidebar. The latter is what I want to do. I don’t want literally two sidebars, just one; but it would be preferable to be able to add widgets with different styling. I looked at the Widget Wrangler plugin, which allows you to create different “sidebars.” But (from what I can tell) they’re not different “sidebars,” they’re different widgets within ONE sidebar. I didn’t find it very intuitive, and I haven’t found any instructions here that are terribly straightforward either. Can someone shed some light on an easy way to style widgets differently in one sidebar?

Thank you.