in the holocaust, millions of jews, as well as roma people (also called "gypsies"), people with disabilities, homosexuals, political opponents, and many other people were sent to concentration camps and death camps in poland and germany. the nazis killed millions of these people at the concentration camps with poison gas. the nazis also killed millions of people in these groups by forcing them to do slave labor without giving them much food or clothing. in total, 17 million people died, 6 million of them being jews.