What is exactly meant by risk reward ratio?

I have seen this term used here frequently.
I did some digging, when you guys say do not risk more than 1-2% of your portfolio on one trade, you are referring to the stop loss. The stop loss should be set as such that if it hits, you do not lose more than 2% of your EQUITY.

But I could not comprehend the concept of risk reward ratio. Does it mean your TP should be twice that of your stop loss for a risk reward ratio of 1:2. Or is there something else?