“For” means you’re in favor of the proposal or director nominee. “Against” means you’re not in favor of the proposal or director nominee. “Abstain” means you do not wish to cast a vote one way or another. In some jurisdiction you can also withhold. “Withhold” is similar to abstain, but is used in instances in which nominees run unopposed and therefore only need a single vote to earn a “plurality.” In these cases, “against” votes are meaningless, so you only have the option to vote “for” or “withhold.”