Same as the difference between any other detachable or clamshell devices. They have usability tradeoffs in different scenarios. A clamshell has better balance

Same as the difference between any other detachable or clamshell devices. They have usability tradeoffs in different scenarios. A clamshell has better balance because of the battery and internals in the keyboard half instead of in the screen. It has better screen angles and is usually smaller and lighter than both parts of a detachable. It doesn't work at all as a tablet though, and a touchscreen is an afterthought.