Holocaust means Jews persecution
Holocaust comes from the Greek Holokauston, which means completely burned. Of origin, this is a voluntary sacrifice of fire to a god. At the Holocaust nothing was sacrificed to a god and it was not voluntary, many people often call it Shoa (destruction). Besides the Jews, others (homosexuals, gypsies, disabled people, etc.) were arrested and murdered in a concentration camp (or extermination camp) during the Second World War. During the Holocaust, 6 million Jews were murdered. More about the war and the Holocaust can be read on the site of the NIOD.