to add to this
@Petunia ,
the House of Representatives is in charge of impeachment, and they did impeach Trump (twice).
once the House votes in favor of impeachment, then it moves to the Senate to vote on whether or not to convict - they need a 2/3 majority to convict, which did not happen with Trump, so he was acquitted.
if conviction does occur, they're immediately removed from office, and a separate vote can be brought to determine whether they're also banned from holding future federal offices. that only needs a simple majority rather than 2/3, but as Trump was not convicted in the Senate, they can't vote to bar him.