When it comes to the U.S. presidential election, it's not the individual voter who counts not exactly but rather the electoral votes that are apportioned to the states.
Depending on who wins the popular vote in a given state, with only two exceptions, the state gives all its electoral votes to him or her.
The number of electors a state gets is determined by how many members it has in Congress, which is roughly proportionate to its population.
For example, California because it has two senators like all other states, and 53 representatives in the House gets 55 votes. The candidate who gets the most votes in California, no matter how close, gets all of them.
So across all 50 states and District of Columbia the numbers vary.
Now, if you add up all the points, the total is 538, this means a candidate has to get at least 270 votes to win.
This is why its possible for a candidate to win the most votes nationally but not win the election.
For example, in 2016, Democratic presidential nominee Hillary Clinton won the nationwide popular vote by nearly 3 million but lost the election to Donald Trump based on electoral votes.
The American Founding Fathers set up the Electoral College to uphold the system of federalism and to ensure that less populous states have some influence.
But by the same token, the winner-takes-all approach means some states are virtually ignored in the campaigns.
"There is no benefit to campaigning to a state you know you're going to lose. So the electoral college focuses all the attention and resources of campaigns onto the states that are evenly divided between Democrats and Republicans. States like Florida, Michigan, Pennsylvania, and Ohio, where nobody knows how they're going to vote at the start of any election cycle… with effort, money and time, either party's candidate could win those electoral votes"
The states that are evenly divided are usually called the swing states.
For this election, there are six of them.
These states will effectively decide the election, though they make up less than a fifth of the electoral votes.
Kim Do-yeon, Arirang News