The Electoral College is basically a group of 538 "electors" selected by each state to vote in the best interest of his/her constituents. Each state gets a minimum of three votes, at least two of which go to the Senators and one of which goes to the House Representative(with the exception of D.C. which has no appointed congressmen). The Electoral College was set up in the United States Constitution and it is believed that the framers did so in order to leave important decisions; such as who will be president; up to the informed, educated elite rather than the common citizen.
There are various problems or weaknesses within the Electoral College and many of them stem from the outdated-ness of this policy. Amongst the weaknesses are: States with larger populations get more votes, thusly eliminating the voice of some of the smaller states; candidates can win the popular vote and still lose the election in two different ways, one being that there is no punishment for a member of the college who does not vote according to the popular vote in his/her state, and the other being that the candidate which wins the majority in a certain state will gain all the votes for that state.
The Electoral College does have a few strengths however , among these are the encouragement of a two-party system, and the fact that there is a mandatory distribution of popular support (impeding any particular region to dominate).