After the polls close, the ballot counting begins.

The vast majority of Georgia votes will be counted on election night, but it will take more time to tally tens of thousands of absentee ballots returned on the last two days of the campaign cycle.

Results will start to show up online about an hour after polls close at 7 p.m. on Tuesday. By midnight, voters will know the outcomes of many races in Georgia. Results in close elections might not be immediately clear.

All ballots must be counted before elections are finalized, a process that always takes a few days to complete in every election. This year’s election is different because so many people are casting absentee ballots that take longer to process than in-person votes.

WATCH: An AJC panel discusses What to expect on Election Day

Credit: HYOSUB SHIN / AJC

Credit: HYOSUB SHIN / AJC

Starting the count

Early votes and absentee ballots processed in advance of Election Day will be among the first votes counted in many counties.

For in-person early votes, election officials gather memory cards from optical scanning machines. These memory cards, which contain votes cast during three weeks of early voting, will be ready to be counted at county election offices after polls close.

Election workers print out a report showing how many votes were cast on each memory card. Then they insert memory cards into a computer server to tabulate votes. These servers aren’t connected to the internet to reduce the possibility of tampering.

Most absentee ballots will also be ready to be counted soon after polls close.

A rule passed by the State Election Board allowed counties to open and scan absentee ballots starting 15 days before Election Day. Then on election night, officials will insert flash drives that contain scanned absentee votes into the server to be counted.

Almost every county in Georgia is processing absentee ballots ahead of time, according to the secretary of state’s office.

In Fulton County, a group of nearly 20 election workers has been preparing absentee ballots in a room in State Farm Arena, also the site of Georgia’s largest early voting site.

After workers verify voter signatures, noisy machines cut open ballot envelopes. Workers separate envelopes from ballots, putting them in trays. High-speed scanners then read voters' selections.

“Scanning ahead of time is a big help,” Fulton Elections Director Richard Barron said. “If we had to do this on Election Day, it would take us a couple of weeks to finish.”

Barron plans to be able to count all absentee ballots received before 2 p.m. on Tuesday on election night.

Vote review panels check ballots that scanning machines flag for ambiguous marks or overvotes — two votes in one contest. Made up of appointees of political parties and the county election superintendent, vote review panels are tasked with determining the voter’s intent.

Credit: HYOSUB SHIN / AJC

Credit: HYOSUB SHIN / AJC

Election Day votes

Votes cast on Election Day are also stored on memory cards attached to scanning machines.

When polls close, election workers print out an initial version of results and post them on the precinct door. Then they collect the memory cards and bring them to the county election office.

“What we end up waiting on is that last poll to come in,” Cobb County Elections Director Janine Eveler said. “There’s always that last poll at the end of the night with a new manager who doesn’t know how to do everything or didn’t get their poll closed as efficiently as they should have.”

It takes time for workers to drive from polling places to election offices to deliver memory cards.

A few years ago, a Cobb elections worker got in a fender bender on the way, Eveler said. Sheriff’s deputies went to the crash scene, collected the memory cards and brought them back to the elections office.

As with absentee and early votes, memory cards are inserted into servers for tabulation.

Poll watchers appointed by political parties are allowed to observe the process for irregularities.

Posting results

Official results are stored on county election servers, but unofficial results still need to be reported to the public.

Votes are saved from the server to a flash drive, then burned from the flash drive to a CD, Eveler said. The CD is then inserted into an internet-connected computer that uploads vote counts to the state’s election website where results are displayed. Other counties may handle the reporting process slightly differently.

The first results from large counties should begin showing up after 8 p.m. Counties in metro Atlanta often don’t finish reporting results until after midnight.

Remaining absentee ballots will be scanned and counted in the days afterward. Court challenges over absentee and provisional ballots could arise again this year, as they did following the 2018 election.

Voters whose absentee ballots are rejected for missing or invalid signatures will be notified, and they have until Nov. 6 to correct problems. Provisional ballots issued to people whose registration couldn’t be verified also have until Nov. 6 to verify their information.

State law gives counties 10 days to complete vote counts, then Secretary of State Brad Raffensperger certifies statewide results a week afterward. During that time, election officials will conduct the first statewide audit of paper ballots to help verify results.

RELATED: How the AJC will report election results

Georgia election timeline

Tuesday: Election Day. Absentee ballots must be returned by 7 p.m. to be counted.

Nov. 13: Deadline for county election offices to finalize results.

Nov. 20: Statewide results will be certified.

Dec. 1: Runoff election, if necessary, for state offices.

Dec. 14: Electoral College meets to cast votes for president.

Jan. 5: Runoff election, if necessary, for federal offices.