Overview
A ui definition in Semantic usually contains a list of mutually exclusive variations on an element design. A type is designated by an additional class name on a UI element
Content
Types may require different html structures to work correctly. For example, an icon menu might expect different content like icons glyphs instead of text to be formatted correctly
HTML Differences
Types may also each require slightly different html. For example, a tiered menu needs html specified for a sub menu to display itself correctly