Democrat Kamala Harris faced Republican Donald Trump on Tuesday in the U.S. presidential election, after the two candidates vied for support by staking positions on issues including abortion, the economy and foreign policy.

Exit polls help us better understand who came out to vote, how different groups of people voted and how they feel about some of the biggest issues of the campaign.

After 5 p.m. Eastern Time on Election Day, Americans will get their first look at exit polls, which could offer early intel in the race between Vice President Kamala Harris and former President Donald Trump for the presidency. But how do exit polls work, and are they reliable? Here’s what to know on Tuesday, Nov. 5.