Both articles are based on the Ukraine scandal, meaning the party decided not to introduce any articles of impeachment solely based on the Mueller report, as some had pushed for. You can read the full articles of impeachment at this link.
Articles of impeachment are essentially the “charges” against the president that the House of Representatives is considering approving. The final House votes on impeachment will be a yes or no vote on each article. If even one is approved, Trump is impeached — and the Senate will then hold a trial to determine whether to remove him from office.
Article I, abuse of power, addresses Trump’s general underlying conduct in the Ukraine scandal. It alleges that Trump abused his power by trying to pressure Ukraine’s government into announcing an investigation into the Bidens by withholding both a White House meeting and military aid.
Article II, obstruction of Congress, is about how Trump responded to Democrats’ impeachment inquiry over the Ukraine scandal. It alleges that Trump obstructed the probe by urging witnesses not to cooperate and government agencies not to comply with subpoenas.
The next step is that the House Judiciary Committee will vote on whether to approve each article later this week — which is mainly seen as a formality, as the committee has a large majority of liberal-leaning Democrats who will clearly approve both articles.
After that, the action will proceed to the House floor, with a final vote on both articles of impeachment expected next week. At least one article, and probably both, are highly likely to be approved by the House of Representatives’ Democratic majority. And that would make Trump only the third president in US history to be impeached.