Ah. So, the House basically does the investigation. Then votes on whether or not there should be a trial.
The trial is actually held in the Senate. The Chief Justice of the Supreme court runs the trial. The Senators present evidence. Argue shit out. Take a vote to remove the President from Office.
If the vote succeeds, Trump is removed from office. If it fails, he stays in the office.
But the really weird part- let's say that Trump is removed from office. The Senate has to take a separate vote on whether or not to bar him from federal service ever again.
So. It's possible for Trump to be removed from office. BUT not barred from public service. So, he could still be the Republican nominee in 2020 for a 2nd term.
This has actually happened. A federal judge was impeached and removed from office (this has happened 18 times, with 8 judges having been removed. the last was in the late 80's). he went back and ran in a congressional election. He won. Went back to Washington as a representative.
Historical note: he voted against the impeachment vote for Clinton in the House.