Washington CNN  — 

Democrats have clinched 50 seats in the Senate, but the stakes remain high for Georgia’s December 6 runoff between Democratic Sen. Raphael Warnock and Republican challenger Herschel Walker.

Neither candidate surpassed the 50% threshold needed to win the race outright in the November general election, forcing a runoff.

But what exactly does that mean? How will the runoff election work? And what would a win or a loss mean for each party?

Here’s what you need to know.

What is a runoff and how does it work?

A runoff is an additional election used to determine the winner of a certain race when neither candidate earns the required threshold for victory – in this case, 50%.

In Georgia, runoffs are more straightforward than general elections in that the candidate with the most votes wins.

Georgia’s top elections official, Brad Raffensperger, said counties are already preparing for the December 6 election, and voters can request absentee ballots starting Wednesday through November 28 via the state’s online portal.

Early voting must begin by November 28 in all counties, but Raffensperger said his office anticipates some counties could have early voting on Saturday, November 26 or Sunday, November 27. “We are working with the counties to find out what their plans are on this front,” he said.

Notably, the logistics of the 2022 runoff will be different than in years passed. The 2021 Georgia law that cut the length of runoffs from nine weeks to four means that the deadline for a new voter to register for the runoff election has already passed.

Gabriel Sterling, the chief operating officer for Georgia’s Secretary of State Office, told CNN’s Paula Reid Sunday evening the cutoff is in place because, “Historically, the state constitution of Georgia lays out that the runoff is supposed to be a continuation of the original election.”

“There’s some responsibility on voters in this thing. The reality is if you’re a registered voter in this state, and we have 7.9 million of them, you’re able to vote in this state whether you vote in the election or not,” Sterling said.

What is at stake?

Put simply, a lot.

With Democrats projected to hold 50 Senate seats, voters in Georgia will determine whether the chamber remains split 50-50 – and runs based on a power-sharing agreement that depends on Vice President Kamala Harris breaking tie votes – or whether Democrats gain the 51 seats needed for a true majority.

Top officials from the Democratic and Republican parties told CNN they intend to double down on their significant investments in Georgia, with an increasing assumption that meaningful control of the Senate could hinge on the outcome of the runoff.

What are the candidates saying?

In brief remarks on Tuesday night, Walker asked supporters gathered in a hotel ballroom to “hang in there a little bit longer.”

“I’m telling you right now – I didn’t come to lose,” Walker said.

Warnock, meanwhile, told supporters early Wednesday morning, “We’re not sure if this journey is over today, or if there’s still a little work yet to do, but here’s what we do know: We know that when they’re finished counting the votes from today’s election, that we’re going to have received more votes than my opponent.”

Both candidates are expected to speak later Wednesday, aides said, with specific plans still in flux.

CNN’s Gregory Krieg and Ella Nilsen contributed to this report.