Fusee Gelee is tethered in that you need a USB connection which can come from a cable, external modchip/dongle, or internal trinket. Deja Vu is tethered in that you need a network connection, whether wireless or wired.Thanks for an answer!
Last question about this, deja vu, fusee gelee, all of Nintendo Switch hacks are tethered?
Or is there some FW (something else?) which provide untethered hack for nintendo switch?