How it works:

When electing a single candidate — such as a race for Governor or a United States Representative — all first choices are tallied. If a candidate wins more than 50% of first-choice votes, that candidate is the winner. If not, the candidate with the fewest first-choice votes is eliminated. Then all voters have their highest available choice counted. This process continues until one candidate receives more than 50% of the vote, or, until all rounds have been counted.  

CHECK OUT THIS EXPLANATORY VIDEO:

Learn More About RCV: Single-winner Elections | Multi-winner Elections