What is the Electoral College?
Each state's political party chooses representatives who actually vote for the
president. The party that gets a majority of the popular vote sends its state's delegates to the state capital in December following the November election. There they cast the official vote for president. When the voters cast their
ballots, they are actually voting for these "electors." The Electoral College
has nothing to do with school, but the Founding Fathers saw these wise party
leaders as a buffer between the voters and the office of the presidency. The
Electors can choose to vote for someone other than the people's choice. These
deviating electors are rare, so they are called "faithless electors."
The winning party for each state sends the number of people equal to the number of people that state has in Congress (two senators plus the number of the state’s delegation to the House of Representatives). These votes are then counted in the Senate on January 6 after the election to determine who will be the next president. There are 538 electoral votes (535 members of Congress and three for the District of Columbia).
270 electoral votes are needed to win the election.
The video on the PBS Website called the.news entitled "Campaign Strategy" has a great explanation of how the Electoral College was formed. how it works, and why it is still in use today.