Technically, there is between the two; they are simply numbered to help you distinguish between the physical ports on the board. Breaking Down the Labels
On modern motherboards, these labels designate the specific pins used to connect your case's front-panel USB ports. usb e12 vs usb e34
Ensure you are using the correct 19-pin cable. If your case uses older USB 2.0 connectors (usually 9-pin), they will not fit into these 3.0/3.2 headers without an adapter. Technically, there is between the two; they are
In industrial automation, Phoenix Contact produces "USB BNC" and "USB E12" or "USB E34" series connectors. there is between the two