Yeah, you are confused about a couple of things.
The first part has to do with Robert Mueller. In May of 2017 he was appointed to conduct an investigation into essentially three things. First, the Russians attempt to undermine and influence the 2016 election. He indicted something like 30 people related to this, most of them Russians who we'll likely never see Justice because their country won't turn them over. The second, he was looking into whether Trump, or anyone else in the Trump campaign, conspired illegally with Russia in their efforts to undermine the 2016 election. In this matter he secured no indictments because he was unable to find evidence which showed an agreement between Trump, or members of the Trump campaign, and Russia. However, he did uncover a fair amount of evidence would show that Trump was extremely welcoming of the Russian assistance in the 2016 campaign and did nothing to stop the Russians. This just did not amount to criminal activity in the opinion of Mueller. He also was supposed to investigate any other matters which might arise from these first two investigations. Basically, that allowed him to investigate issues of obstruction of justice and perjury. He has secured indictments and convictions on a couple of trump Associates, most prominently Trump's First National Security advisor retired General Michael Flynn, and longtime Trump advisor Rodger Stone. These men were both convicted for what are known as process crimes, essentially perjury in their sworn statements to authorities. Trump's onetime campaign manager, Paul manafort, was convicted of failing to register as a foreign agent and money laundering which was discovered during the Mueller investigation but was not directly related to the 2016 election. Rodger Stone conviction just came down today. That is presumably what you are referring to when you mentioned hearing about someone lying under oath. Stone was charged with perjury 4 lies which she told investigators and Congress in the investigation of the 2016 election. Specifically, Stone had been involved in efforts to contact Wikileaks, a transparency organization which was acting as a Russian front during the 2016 election. Stone wide about some of the things which he did in relation to this, including about whether he had informed members of the Trump campaign about his efforts. He had informed them and had claimed that he had not.
The impeachment inquiry going on now is not directly related to the Russia investigation or the 2016 election. What happened is that about two months ago, news broke that the White House was withholding a whistleblower report from the House of Representatives. A CIA officer had filed a whistleblower report of unknown content. What happens is that this report is reviewed by the inspector-general of the CIA to determine whether it's credible or not. Having determined that the report was credible, the CIA is supposed to turn that report over to the relevant congressional committees. The White House was refusing to do that. Shortly after this story broke, the content of the whistleblowers report was released. The Whistleblower claimed that during a phone call with the Ukrainian president back in July of this year, Trump had pressured the ukrainians to open up an investigation into Hunter Biden, the son of former Vice President Joe Biden who is now running for the Democratic nomination for president. Several years ago, Hunter Biden had been on the board of directors of a Ukrainian oil and gas company that was investigated by the Ukrainian government for potential Financial misconduct. The investigation ended with no charges being brought against the company and Hunter Biden himself was never actually investigated or suspected of any wrongdoing. Never the last, Trump had pressured the Ukrainian government to reopen the investigation. He also pressure them to open an investigation into a discredited right-wing conspiracy theory which says that the Russian hacking of the 2016 elections was really a sort of elaborate frame-up job by the Ukrainian government in coordination with the Democratic Party. The Whistleblower thought that this effort to enlist what was essentially help with Trump's political campaign was an illegitimate use of state power and filed a whistleblower complaint. The soon after this story broke, Trump released a transcript of the call which essentially confirmed the whistleblowers claims about its content. House Speaker Nancy Pelosi, who had previously been reluctant to discuss impeachment, pretty much immediately authorized in impeachment inquiry. The house has conducted several weeks of closed-door testimony, much of which lead to the public, where Witnesses have fleshed-out a **** by President Trump, and spearheaded by his private attorney Rudolph Giuliani, to pressure the Ukrainian government into helping out Trump's campaign by investigating the family of Joe Biden, who at the time was leading me primaries to game the Democratic nomination. The most significant part of the spot was the White House's decision to withhold several hundred million dollars in military aid which Congress had appropriated to Ukraine. The ukrainians have been engaged in a low-grade war with Russia since 2014 when demonstrations in Ukraine overthrew the pro Russian president there. Russia responded by invading an Annex seen the Crimean Peninsula and fomenting a separatist rebellion in the eastern part of Ukraine which is heavily populated by ethnically Russian people. The US has been allied with Ukraine and has recently stepped up its efforts to provide them with weapons to help fight the Russians. Trump withheld this money for several months and on the phone call he seemed to indicate that releasing it would be contingent upon Ukraine approving these investigations. There were also other element switch they used to try and pressure Ukraine. The ukrainians elected a new president earlier this year. Vice president Mike Pence was supposed to fly to the Ukrainian capital of Kiev to attend the president's inauguration. Instead, the White House downgraded the American presence to Energy Secretary Rick Perry. While not Material important, this carry symbolic political wait. Do Ukrainian president was also seeking to gain a personal audience with President Trump in Washington which would help boost his legitimacy back home. While elected by a popular Landslide, the Ukrainian president is not a professional politician but a comedian, who ironically played a Ukrainian president on TV. Having me present in the United States publicly vouch for him in a public meeting would be a major boost for his reputation. Trump also withheld such a median in order to try and get these investigations off the ground. There also are issues of them trying to hide evidence. After this phone call occurred, White House lawyers pad the transcript of it stored on a super secure server which is only accessible by a relative handful of people. This is in contrast to most White House foreign calls where they are stored on a less secure server with access available to a broad variety of state department and foreign policy professionals. Usually, the calls which are put on to this secure server are ones where discussion of sensitive intelligence or military matters occurs but no such discussion happened on this phone call.
The Democratic argument here is that this is basically extortion with Trump using his official Powers as president trying to get what is essentially a form of campaign contribution from the Ukrainian government. By investigating Joe Biden son they would presumably introduced to notice candle to buy this campaign and we can him against President Trump. the Republican response has been much less coherent, in part because the facts are running against them. Some of them have tried questioning the whistleblowers motives, but this is been unproductive because the facts that The Whistleblower testified to of all been confirmed by other sources. Some of them have tried turning this around on Joe Biden and his son or have tried to argue that this was part of a broad effort to combat corruption. However, this is undermined by the fact that Trump did not express any interest in corruption broadly, or in any other corruption in Ukraine other than that allegedly involving his political Rivals son. Others have been trying to argue that we should just ignore this because Democrats have a partisan motive to go after Trump. The defense which Republicans seem to be settling on, partly by virtue of it being the only one that they have left, is that Trump did The defense which Republicans seem to be settling on, partly by virtue of it being the only one that they have left, is that Trump did what he's been accused of doing, and that it was wrong, but the discussion tries to the level which would require impeachment.