Washington (CNN) Robert Mueller is set to testify publicly Wednesday about his report on Russian interference in the 2016 election .

Here's what you need to know about the hearings and former special counsel.

When and where

Mueller will first appear before the House Judiciary Committee at 8:30 a.m. ET, and the hearing is expected to run for three hours. After a short break, Mueller will then testify before the House Intelligence Committee at noon ET.

The Intelligence committee, chaired by Democratic Rep. Adam Schiff, will focus on Russian interference in the election, or Volume 1.

Each lawmaker will get five minutes to ask Mueller questions. The Judiciary Committee will attempt to squeeze all 41 of its member's questions into three hours, so some members may not take up their full allotted time.

Democrats want to illustrate the report's findings -- including that Mueller could not clear President Donald Trump of a crime when it came to obstruction of justice -- and Republicans want to focus on the conclusion that the Trump campaign did not take criminal steps to help Russians interfere in the 2016 election.

Mueller was subpoenaed by House Democrats, who are hoping his testimony will shift public perception about Trump's alleged criminal activity outlined in Mueller's report.

Who is Robert Mueller?

Mueller is a Vietnam veteran who rose through the ranks at DOJ and later became FBI director under President George W. Bush.

When Mueller's 10-year term as FBI director came to an end, then-President Barack Obama asked Congress to allow him to keep Mueller on, and Congress unanimously approved.

Mueller stepped down from the FBI in 2013, and was succeeded by James Comey.

In May 2017, Mueller was appointed as special counsel shortly after Trump fired Comey . He was authorized to investigate Russian interference in the 2016 election, whether any Trump associates coordinated or colluded with the Russians, whether Trump obstructed the investigation and any other crimes that were uncovered during the investigation.

Mueller's selection as special counsel was met at first with bipartisan praise, but as the investigation wore on, Mueller became a frequent target of Trump and his allies.

He spent nearly two years investigating Russian interference in the 2016 election -- he interviewed about 500 witnesses, and obtained more than 3,500 subpoenas and warrants of various types -- and delivered his report in March.

How much Mueller will expand beyond the report remains to be seen. In a letter Monday, the Justice Department told Mueller his testimony "must remain within the boundaries of your public report because matters within the scope of your investigation were covered by executive privilege."

What is in Mueller's report?

Mueller brought criminal charges against six Trump associates, 25 Russians who interfered in the election, three Russian companies and three others. The Trump associates were: senior campaign officials Paul Manafort and Rick Gates, national security adviser Michael Flynn, former fixer Michael Cohen, longtime ally Roger Stone and campaign adviser George Papadopoulos. Some of these defendants are already in prison, other cases are still ongoing.

Mueller said he could not clear Trump of obstruction of justice, but that charging the President was not an option his office could consider.

The former special counsel's probe found members of the Trump campaign knew they would benefit from Russia's illegal actions to influence the election, but did not take criminal steps to help.

"If we had had confidence that the President clearly did not commit a crime, we would have said so," Mueller said in a rare public statement in May. "We did not, however, make a determination as to whether the President did commit a crime."

JUST WATCHED Mueller: Russia launched attack on our political system Replay More Videos ... MUST WATCH Mueller: Russia launched attack on our political system 02:08

Mueller delivered a road map of how the investigation played out and the possible role that Congress could play in holding Trump accountable. In his May speech, he highlighted how the "Constitution requires a process other than" the criminal justice system to hold officeholders accountable, a clear signal his obstruction investigation into Trump could be carried on by Congress.

What does it mean for impeachment?

Democrats remain deeply divided on whether to pursue impeachment against Trump, and Mueller's public testimony could inform whether more Democrats decide to back an impeachment inquiry.

More than 80 House Democrats have called for an impeachment inquiry since a redacted version of Mueller's report was released by the Justice Department in April.

House Speaker Nancy Pelosi, however, has been reticent to push for impeachment, and a low-key appearance by Mueller could mean the idea loses steam.

Will President Trump be live-tweeting?

The President last week said he wasn't going to watch the testimony. Monday, he said he might see a bit.

"No, I'm not going to be watching. Probably. Maybe I'll see a little bit of it," Trump told reporters in the Oval Office. "I'm not going to be watching Mueller because he can't take all those bites out of the apple. We had no collusion, no obstruction, we had no nothing. We had a total no collusion finding. The Democrats were devastated by it. They went crazy, they went off the deep end, they're not doing anything."