1R is what you risk on a trade: the distance between your entry and your stop loss, in money. If you enter risking $200, then 1R = $200 for that trade.
In money, a $500 win looks better than a $300 one. But if the first risked $500 (1R) and the second risked $60 (5R), the second trade was far better. In R you see it instantly; in dollars you do not.
It also takes the emotion out of the money. "I lost 1R" hurts less than "I lost 400 euros", and lets you think with your head instead of your stomach.
In Onyx Guardian you can set your levels in R. That way break even or trailing adapt to each trade without you recalculating pips.
Onyx Trading Live