Because impeachment and conviction of officials involves an overturning of the normal Constitutional procedures by which individuals achieve high office (election, ratification, or appointment), it is usually only reserved for those deemed to have commited serious abuses of their office. In the United States, for example, impeachment at the Federal level is reserved for those who may have committed "high crimes and misdemeanors". Several Federal officials, including two Presidents and several judges, have been impeached over the course of US history.
Impeachment has its origins in English law. It exists under constitutional law in many nations around the world, including the United States, Russia, and the Philippines.