The USC Shoah Foundation Institute is the largest collection of video testimony on the Holocaust. The Holocaust is one of the events that will forever define the 20th century.
Holocaust was once a general term used to describe massacres and mass slaughter. During World War II the term was applied to all Nazi atrocities. In the last forty or fifty years the term has been narrowed specifically the the genocide of Jews.
No matter how you partition and name the crimes of the Nazis the numbers are staggering. 6 million Jews, over 2 million Soviet POWs, over 1.8 million Poles, up to a quarter of a million disabled, and that's only the beginning. The estimates of the number of Romani killed varies wildly between 220,000 and 1.5 million. The number reaches 11 million people in total.
If you go beyond the Holocaust and look into civilians killed in Nazi occupied areas during the war the numbers keep growing. One estimate adds another 6 million Soviet civilians. Taking the count to the logical extreme and the estimates of the Nazi death toll for non-combat related deaths (democide - which includes genocide, politicide, and mass murder) is a staggering 21 million.
Much has been written about the Holocaust since the war. Much of the material consists of personal memoirs and stories. There is so much material that scholarly works can be based on nothing but how to understand the works available. Introduction to and Bibliography of Central European Women's Holocaust Life Writing in English by Lousie Vasvari is an example.
The unspeakable has to be recorded and remembered. Countless books and memoirs have been written on the Holocaust. Yet there is something fundamentally more moving about watching and listening to survivors. Sometimes books don't have the same impact as watching a person tell their story.