Each voter may vote for (approve of) as many of the candidates as they wish. Each voter may vote for any combination of candidates and may give each candidate at most one vote.
How the Results are Calculated
A simple vote counting algorithm in which ballots are counted and the winner is the candidate or candidates who are the most-approved. When running a multi-seat election (3 directors are elected from 7 candidates) the candidate with the highest approval will win the first seat, the second-highest percentage approval wins the second seat, and so on, until all seats are filled.
For further details visit Approval Voting on Wikipedia