Options vs appearance

What is the difference between options and appearance in BS?

In a nutshell, the settings in the Options panel change the appearance/behavior of components by adding Bootstrap utility classes to them, whereas the settings in the Appearance panel change the components by adding inline CSS rules to the HTML. When you change something through the Appearance panel, you will typically want to extract the newly created inline CSS and add it to an external style sheet.

Nothing you do in the Options panel will result in any inline CSS being created.