.

Keeping this in view, what is an Rgh?

RGH stands for Reset Glitch Hack it's a tiny reset pulse to the processor while it is slowed down does not reset it but instead changes the way the code runs, it seems it's very efficient at making bootloaders memcmp functions always return "no differences".

Beside above, what's better JTAG or RGH? Overall, RGH is a more convenient method, but the JTAG boot times are more stable where as RGH can take 5 minutes one boot then 2 secods the next. JTAGable Xbox's are also much more difficult to find these days, were as RGH is considerably easier to find.

Beside above, can you Rgh a Xbox one?

RGH Xbox One JTAG: As the Xbox One JTAG is patched by the creators, you will not get banned. Xbox One JTAG will be compatible with the mod of almost all the models such as the new and old Xbox One consoles. You can use the Xbox One console without any downgrade version or hardware required.

Is a Rgh illegal?

It is completely legal to have one. Its only illegal if you use it to get free games, modify gameplay, etc. There is way more things you can do with a jtag/rgh/devkit than just modifying online/offline gameplay. Yes sorry for giving little detail.