From the Summary: "Under the U.S. Constitution, the House of Representatives has the power to formally charge a federal officer with wrongdoing, a process known as impeachment. The House impeaches an individual when a majority agrees to a House resolution containing explanations of the charges. The explanations in the resolution are referred to as 'articles of impeachment.' After the House agrees to impeach an officer, the role of the Senate is to conduct a trial to determine whether the charged individual should be removed from office. Removal requires a two-thirds vote in the Senate. The House impeachment process generally proceeds in three phases: (1) initiation of the impeachment process; (2) Judiciary Committee investigation, hearings, and markup of articles of impeachment; and (3) full House consideration of the articles of impeachment."
CRS Report for Congress, R45769
Congressional Research Service: https://crsreports.congress.gov/