Incumbent U.S. President Donald Trump us trailing in the Electoral College vote by 214 to 264 after Democratic candidate Joe Biden flipped the key states of Michigan and Wisconsin and retained a lead in Arizona.

Flip is a term used to indicated the states that changed party allegiance compared to the 2016 election.

Authorities are still counting the votes in Georgia North Carolina, Pennsylvania and Alaska, where Trump is currently leading, as well as Nevada where Biden is leading, according to a chart prepared by The Guardian.

The winner of the election is determined through a system called the electoral college. Each of the 50 states, plus Washington DC, is given a number of electoral college votes, adding up to a total of 538 votes. More populous states get more electoral college votes than smaller ones. A candidate needs to win 270 electoral college votes (50% plus one) to win the election.

In every state except two – Maine and Nebraska – the candidate that gets the most votes wins all of the state’s electoral college votes.

Due to these rules, a candidate can win the election without getting the most votes at the national level. This happened at the last election in 2016, in which Trump won a majority of electoral college votes although more people voted for Hillary Clinton across the U.S.