about impeachment

Impeachment is the equivalent of a grand jury indictment; in a normal criminal case, a prosecutor obtains an indictment against an individual from a grand jury, and then the case is tried by a court for a verdict of guilty or innocent.  Similarly, the US House of Representatives may impeach a federal official, and then the case is tried by the US Senate for a verdict of guilty or innocent.  Two US Presidents have been impeached (Andrew Johnson and Bill Clinton); both of them were found not guilty by the US Senate.