Difference between passthrough & real wiimote?

[TNU2002]

In controller settings, there are two options for Wiimotes:
1. Passthrough a Bluetooth adapter
2. Real Wiimote (Emulate the Wii's Bluetooth adapter)

Which one do I pick and how are they different? I have a Wiimote, usb sensor bar, and usb bluetooth dongle (for the wiimote).
Thx