Usually voting means that the majority rules, but not always. Sometimes organizations operate on consensus, meaning that everyone agrees on something before it moves forward. It sounds so nice and friendly in theory, but in practice it has often been used to exclude. One person's strident opinion can override the will of the rest.
This ballot box that was once used by the Delta Kappa Epsilon fraternity was the mechanism for assuring unanimous consent at the fraternity. New members were elected through a secret ballot using a specially designed box. On one side were black and white marbles, with a small hole connecting to the other side. Each member of the fraternity would place his hand in the box, select a white or black marble, and push it through to the other side. When the voting was complete, the members opened the other side of the box. If all the marbles were white, the new member was accepted, but, if there was a single black ball, the member was rejected. Ironically, this system where a minority could veto the majority was part of a system of institutionalized racism that could easily exclude any member because of his race or religion.
This system was phased out in the 1950s and 1960s as the Dartmouth fraternity system worked to end the practice of blackballing prospective members based on race or religion.
To see the ballot box, ask for DO-37, Box 13146. It is cool and frightening at the same time.