depends on what you mean by who is Donald trump. It also depends on your political persuasion if your left wing he is the devil incarnate, the man you wouldn't trust to leave your children with when your in the other room. contrary is you are right wing he is the greatest ting since sliced bread and the rock on which a modern America should be built upon
first lets see who he is as a person, he is 77 years old who google values at $2.55 billion he is a house hold name and former us president, the first to get 2 impeachment trials against him. he has 5 children the oldest born in 1977 and the youngest born in 2006.
Now politically he is a republican who rode the wave of popularism to get elected president of the united states in 2016 after Obama served his 2 term limit, he went up against the wife of former president bill Clinton, she was the first wife to run for the presidency, and is to the best of my knowledge the first and only one to do so, but they were the two lowest rated presidential nominees selected by their parties in living memory and polling only proved this point. he was the first outsider to politics to get elected president since Eisenhower after the second world war.
During his presidency he introduced monumental changes in America executive order 13769 titled Protecting the Nation from Foreign Terrorist Entry into the United States, labelled the "Muslim ban" by Donald Trump. it basically stooped from Muslim countries from entering the us, until the supreme court ruled it an unconstitutional order and banned it implementation
his famous border wall went far as well building only 83 more miles than existed that is basically the distance from Cambridge to London or Washington to bel air the place famous from the fresh prince of bel air so not that far considering the promise he made to secure Americas borders
but in all fairness he did keep 2 promises
he moved the us embasy in Israel from tel Aviv to Jerusalem and pull america out from the paris agreement.
so who trump is is open to debate
hope this helps