Here's the 2nd 2020 Democratic presidential debates schedule and lineup

Ahead of the second of the Democratic 2020 presidential primary debates, candidates redoubled efforts to ensure they met critical fundraising and polling thresholds to make it on stage in the hopes of distinguishing themselves from their competitors and pitching their campaigns to millions of voters.

The debates are Tuesday and Wednesday and the DNC announced who made the stage earlier this month.

Here's what you need to know about the upcoming debates:

When and where are the second DNC debates?

The second of the Democratic party's 2020 primary presidential primary debates are at 8 p.m. ET July 30-31 in Detroit. The July debates will be hosted by CNN and CNN en Español. CNN chief political correspondent Dana Bash, "The Lead" anchor and chief Washington correspondent Jake Tapper and "CNN Tonight" anchor Don Lemon will moderate both debate nights.

Twenty candidates will participate over the two nights, with 10 candidates appearing each night.

Candidates were informed as to whether they will be participating in the debates, one day after the last day to qualify for them. CNN determined the lineup through a live drawing.

How do candidates qualify for the second debates?

The Democratic National Committee announced in February the thresholds required to gain entrance into the party's first two presidential debates, setting benchmarks for polling and grassroots fundraising that represent the first tangible effort to pare down an already crowded field of candidates. The third Democratic primary debate will be hosted by ABC News in partnership with Univision and is scheduled for Sept. 12-13. The qualifying rules are different for this debate, and the fourth debate in October.

In order to qualify for the debates at the end of July, candidates must earn at least 1% support in three separate national or early-state polls conducted from Jan. 1 to two weeks before the given debate, which is Tuesday for the upcoming debates, or receive donations from at least 65,000 people across 20 different states, with a minimum of 200 unique donors per state.

The number of debate participants has been capped at 20 by the DNC.

Who will be participating in the second debates?

The DNC announced Wednesday the 20 candidates who will be debating in Detroit, and CNN assigned those participants to stages and podium placements over the two nights.

The candidates appearing on the first night of the debate, on July 30, with Vermont Sen. Bernie Sanders and Massachusetts Sen. Elizabeth Warren in the center of the stage, are:

The candidates appearing on the second night of the debate, on July 31, with former Vice President Joe Biden and California Sen. Kamala Harris in the center of the stage, are:

California Rep. Eric Swalwell, who dropped out of the race on July 8, had also qualified for the debates after crossing the polling threshold. Even if he stayed in the race, Bullock edged Swalwell out for the 20th spot on the stage for the second debates, according to the DNC's tiebreaker rules, since Bullock had received 1% in more polls than Swalwell.

Who won't be on the debate stage?

There are five candidates who viewers won't be seeing on either night.

While former Alaska Sen. Mike Gravel qualified based on the grassroots fundraising threshold, according to his campaign, he only had one poll with 1% support, and polling takes primacy over the donor threshold, according to the DNC.

The other candidates who won't be on stage after failing to meet either threshold are Tom Steyer, the latest to enter the race; Massachusetts Rep. Seth Moulton; former Pennsylvania Rep. Joe Sestak; and Miramar, Florida, Mayor Wayne Messam.

What are the rules for the debates?

Candidates will have an opportunity to give both opening and closing statements and have two hours to debate on stage, CNN said. The presidential hopefuls will have 60 seconds to answer questions from the moderators and 30 seconds to respond to follow up questions and rebuttals. If invoked by name by another candidate, the candidate will have 30 seconds to respond. Candidates who repeatedly interrupt will have their time reduced, according to CNN.

As far as types of questions, CNN said there would be "no show of hands or one-word, down-the-line questions," which were done during the first debates hosted by NBC, MSNBC and Telemundo.

How would the DNC have winnowed down the field if more than 20 candidates qualified?

If more than 20 candidates qualified, the DNC said those who met both qualifying thresholds will be the first to make the stage. After that, the candidates who have the highest polling average based on their top three polls will qualify. If there are still spots left after that, candidates with the greatest number of unique donors will qualify.

In the event that multiple candidates have the same polling average and there needs to be a tiebreaker to determine who gets the remaining spot(s), the candidates will be ranked based on who has the greatest number of polls with at least 1% support. Those who have the most will make the stage first.

Are the DNC rules the same for the later debates?

In December, prior to the much of the current field's entry into the race, Perez revealed the party's plans to hold a total of 12 debates and split the early events into separate sessions to accommodate the expected quantity of candidates. Six of the Democratic Party's 12 debates will take place in 2019 and six in 2020.

For the next round of debates happening later this year, the DNC announced new, more stringent qualifying rules that up the ante to qualify for the September debate, hosted by ABC News and Univision, and for the debate to follow, slated to take place in October.

In order to qualify for the September and October debates, the DNC requires candidates to meet both polling and grassroots funding criteria, and have doubled the thresholds: a candidate must receive 2% or more support in at least four national polls or polls out of Iowa, New Hampshire, South Carolina and/or Nevada, and candidates must have received donations from at least 130,000 unique donors over the course of the election cycle, with a minimum of 400 unique donors per state in at least 20 states.

The new qualifying rules ramp up the pressure on many in the crowded Democratic field, which has grown to 25 candidates total.

Will there be a climate debate?

Inslee, who is centering his campaign on the issue of climate change, has repeatedly urged the DNC to make one of the 12 presidential debates solely focused on climate policy. But after repeated calls from the Washington governor, activists, top members of the committee, and even several candidates signaling their openness to a climate debate, DNC Chair Tom Perez said he would not amend the current rules to include one this cycle, instead saying that climate change will be featured front and center during this cycle's debates.

But at a July meeting of the DNC's executive committee, party leaders asked the organization to consider a proposal that allows the candidates to participate in a climate debate (not necessarily hosted by the DNC) without facing penalty. It will be decided on at the committee's August meeting.

ABC News' Adam Kelsey and John Verhovek contributed to this report.