each player in the candidates is a "candidate" who's trying to win the tournament so they can play for the WCC, just like there are presidential candidates, and in the World Championship usually it's the World Champion trying to defend his title and there's the challenger from the Candidates who's trying to win the World Championship just like the president is running to keep his office (well, not this year), and there's someone else trying to win the Presidency. And on that note, the president this year is stepping down and there's two new people trying to win the Presidency just like how last year Magnus Carlsen stepped down from the World Championship and two Candidates players were playing for the World Championship. Also I find it interesting how the Elections and the WCC are happening in the same month in the same year.
I just wanted to share this with u all. Happy Election day!