To remove them from officeTo level charges against themTo find them guilty of a crimeTo slander them
The impeachment process is really more of an indictment than anything else. In the US, there have been 19 impeachment trials on the federal level, but only eight convictions.
The PresidentThe President and Vice PresidentThe President and federal judgesAny civil official
Though high profile impeachment cases usually involve federal government officials, state governments can also impeach their elected officials, including governors.
Murder, treason, and extreme executive overreachTreason, bribery, and other high crimes and misdemeanorsTreason, murder, and other high crimes and misdemeanorsTreason, bribery, and other crimes again humanity
The "high crimes and misdemeanors" part is a carry-over from British parliamentary law and doesn't have a clear definition, which has led to partisan quibbling in the past.
The charges against an elected officialThe terms by which the impeached official should leaveThe rules for impeaching an elected officialOp-eds by government officials calling for impeachment
Articles of impeachment were drafted against three U.S. Presidents: Andrew Johnson, Richard Nixon, and Bill Clinton.
A national public voteA vote by the electoral collageA filibuster on the senate floorA majority vote in the House of Representatives
The House of Representatives is the only government body with the power to impeach a federal official. Usually the House Judiciary committee will review the charges, which can be brought by any member of the House.
The House of RepresentativesThe Senate
While the House begins the impeachment process, the Senate is the body that gets to hear the case and rule on a decision.
Andrew JohnsonRichard NixonBill ClintonNone of the above
The Judiciary Committee had approved three articles of impeachment: obstruction of justice, abuse of power, and contempt of Congress. But just before the House could vote on a trial, Nixon resigned on August 9th, 1974.
The Majority leaderThe Minority leaderThe WhipThe Chief Justice
During the Senate hearing, some members of the House act as the prosecution and the Chief Justice of the Supreme Court oversees proceedings.
Two-thirds Senate majorityThree-fourths Senate majorityMajority popular voteThe presiding judge rules
This is known as a supermajority, which is only required in the Senate for certain situations, like ratifying an amendment or overriding a presidential veto.
If found guilty, an official is removed from their post and can be barred from holding future office, but won't serve any jail time. A separate criminal case would have to be filed for that to happen.