orientation
By default, dividers are horizontal and should be used for separating content vertically. The vertical divider is used to separate content horizontally.
size
The small divider is the default size. This is used to divide similar components such as table rows, action button groups, and components within a panel.
The medium divider is used for dividing subsections on a page, or to separate different groupings of components such as panels, rails, etc.
The large divider should only be used for page titles or section titles.