Risk-reward ratio (R:R)
The risk-reward ratio compares what you risk to your stop with what you target to your objective. 1:2 means aiming for twice your risk.
If your stop is 30 pips away and your target 60 pips, your R:R is 1:2. You calculate it before entering, from logical market levels, not by moving the target to get a nice number.
R:R alone says nothing about profitability. It has to be combined with your win rate. At 1:2, you can be profitable with just over one winning trade in three, costs included. At 1:1, you need more than one in two.
A high R:R usually comes with a lower win rate. The balance between the two is called expectancy.