Both! People are often confused by the impeachment process. The easiest way to explain it is that when the House of Representatives impeaches a president it amounts to a criminal indictment. read more
He resigned. But he resigned because impeachment and eventually, conviction, was certain in the minds of a majority of Congressmen. There were articles of impeachment passed by the House Judiciary Committee. A trial date was being set, but that as far as the impeachment process went. Nixon resigned before the impeachment trial could be convened. read more