An electoral vote is a ballot cast by an official state elector in a presidential election. A candidate needs at least 270 electoral votes to be elected president in the U.S.
In the U.S., presidential elections don't rely on the popular vote, which is a direct election in which each voter casts a ballot. Instead, it's the electoral vote, in which members of the Electoral College cast their votes, that decides the winner. Each state has the same number of electoral votes as it has members of Congress, giving the country a total of 538 electoral votes. Electoral is from elector, or "voter," and a Latin root meaning "select."