The Electoral College is a group of specially selected voters who actually elect the President and Vice President of the United States. This system was designed to ensure the indirect election of the President. Historically, it is the result of a compromise between the election of the President by Congress or election by popular vote. Here's how it works:
Citizens vote for the presidential and vice presidential team of their choice on the Tuesday after the first Monday in November. However, they are really selecting "electors" who will actually elect the president and vice president of the United States. The chosen electors of each state will meet on the first Monday after the second Wednesday in December to cast their votes for president and vice president.
To learn more about the Electoral College see the following resources at the National Arhives and Records Administration's Website: