What is RNG and RORG?

Ohh thanks for the reply, btw off topic abit:-

I just started playing back D3 RoS, and reroll as WD. Currently at lvl50+ Should i beat all the difficulties of the game until "Master" lvl or higher. Or should i just get to lvl70 asap and began farming for items? Been away for too long, alot has change, unsure on where to go about.

Thanks for the advice in advance.

So, should i just grind through all the difficulties first? Even when i hit lvl70.