Do you mean RGH (Reset Glitch Hack)? If so, the difference between RGH and JTAG is the way the hack is performed.
They both do the exact same thing, run unsigned code.
RGH can be performed on any dash but boot times vary and JTAGs boot instantly, thats pretty much all the difference that you will notice.

I did mean rgh. But is the console any different?

-hittg- wrote I did mean rgh. But is the console any different?

The console is not any different, but there are different types of RGHs and JTAGs. The motherboard is what determines that. You need to know the following when deciding what to buy.

There are seven types of motherboards, six can be glitched at the moment. This is the order from oldest (most likely to red ring) to newest (least likely to red ring).
Xenon-Oldest, no HDMI, can overheat easily
Zephyr-Same as the Xenon except with HDMI, and possibly better cooling
Opus-The same as a Falcon except it has no HDMI
Falcon-Not likely to red ring, second newest of phat consoles
Jasper-Last of the phat consoles, least likely to red ring among phat consoles
Trinity-First Slim motherboard, very unlikely to red ring, can only be RGHed
Corona-Newest motherboard, supposedly it can be RGHed but I dont think it is fully released

If getting a JTAG at least get a Falcon.
RGHs vary a lot though. Some Jaspers boot really fast some dont, same for RGHed Falcons.
I would really recommend a Slim if your getting an RGH, its worth the extra money.

Thanks for the help man I really appreciate it

and if u need a slim rgh i have a seller hes legit and got me a sweet deal messege me for more info