When you cast your vote for President of the United States, you are not voting directly for a candidate. Instead, your vote — and the votes of everyone else in your state — directs the votes of the people who actually vote directly for President: presidential electors, otherwise known as members of the Electoral College.
The presidential electors are 538 people selected from all 50 states and the District of Columbia to elect the President of the United States. Members of the Electoral College vote on behalf of a given state for the candidate that wins that state’s popular vote.
Source and for more information check out One Person, One Vote: How does the electoral college work?
