They're all LED displays. The nano ones are just smaller, which is what you need to make smaller displays while keeping the resolution the same.
Those video walls you see in stadiums and Times Square and everywhere else today are LED displays, except they use non-micro (i.e. bigger) LEDs so they're big and/or low resolution. I have a couple of the panels, they're squares with 30 cm sides and 64 x 64 LEDs. A few TV manufacturers made high res video walls with the smallest LEDs they could make, which at the time came out to 150" 4K displays. It looks like they've whittled that down to 75" or so now.
Quantum dots are hunks of semiconductor pretty much like all other LEDs except they're so small their size influences the colour they emit. You don't have to change the materials to tune the bandgap, you just change their size. So if you want to make LEDs really small you're eventually going to end up with quantum dots. To be fair, the dots are about 5 nm across, so they are nano. You'd never make single dot pixels for a TV though.