The Parteiflagge design, with the centred swastika disc, served as the party flag from 1920. Between 1933 (when the Nazi Party came to power) and 1935, it was used as the National flag (Nationalflagge) and Merchant flag (Handelsflagge), but interchangeably with the black-white-red horizontal tricolour. In 1935, the black-white-red horizontal tricolour was scrapped (again) and the flag with the off-centre swastika and disc was instituted as the national flag, and remained as such until 1945. The flag with the centred disk continued to be used after 1935, but exclusively as the Parteiflagge, the flag of the party.
Auschwitz I (or "the Main Camp") was the original camp. This camp housed prisoners, was the location of medical experiments, and the site of Block 11 (a place of severe torture) and the Black Wall (a place of execution). At the entrance of Auschwitz, I stood the infamous sign that stated "Arbeit Macht Frei" ("work makes one free"). Auschwitz I also housed the Nazi staff that ran the entire camp complex.
I had become aware of antisemitism from a young age, when my uncle had his head chopped in two when he was attacked by fascists while driving up to Novograd where he lived. While his attacker was convicted, he was hardly punished, and continued to live opposite my uncle’s wife and child. But as a child you don’t think about these things all that much. My family had a wood and coal business and, like most people in those days, my father was self-employed. As they started to restrict us, he lost his licence to operate and then he faced the enormous task of trying to find work. Meanwhile, my mother was at home trying to keep the family together, with all of us all involved in domestic life.

The Generalplan Ost ("General Plan for the East") called for deporting the population of occupied Eastern Europe and the Soviet Union to Siberia, for use as slave labour or to be murdered.[321] To determine who should be killed, Himmler created the Volksliste, a system of classification of people deemed to be of German blood.[322] He ordered that those of Germanic descent who refused to be classified as ethnic Germans should be deported to concentration camps, have their children taken away, or be assigned to forced labour.[323][324] The plan also included the kidnapping of children deemed to have Aryan-Nordic traits, who were presumed to be of German descent.[325] The goal was to implement Generalplan Ost after the conquest of the Soviet Union, but when the invasion failed Hitler had to consider other options.[321][326] One suggestion was a mass forced deportation of Jews to Poland, Palestine, or Madagascar.[317]
In early February, the Polish Red Cross hospital opened in blocks 14, 21, and 22 at Auschwitz I, headed by Dr. Józef Bellert and staffed by 30 volunteer doctors and nurses from Kraków, along with around 90 former inmates. The critically injured patients—estimated at several thousands—were relocated from Birkenau and Monowitz to the main camp. Some orphaned children were adopted by Oświęcim residents, while others were transferred to Kraków, where several were adopted by Polish families, or placed in an orphanage at Harbutowice.[254] The hospital cared for more than 4,500 patients (most of them Jews) from 20 countries, suffering from starvation, alimentary dystrophy, gangrene, necrosis, internal haemorrhaging, and typhoid fever. At least 500 died. Assistance was provided by volunteers from Oświęcim and Brzeszcze, who donated money and food, cleaned hospital rooms, delivered water, washed patients, cooked meals, buried the dead, and transported the sick in horse-drawn carts between locations. Securing enough food for thousands of former prisoners was a constant challenge. The hospital director personally went from village to village to collect milk.[254]
Families, who had disembarked together, were quickly and brutally split up as an SS officer, usually, a Nazi doctor, ordered each individual into one of two lines. Most women, children, older men, and those that looked unfit or unhealthy were sent to the left; while most young men and others that looked strong enough to do hard labor were sent to the right.

The first gas chamber at Birkenau was in what prisoners called the "little red house" (known as bunker 1 by the SS), a brick cottage that had been converted into a gassing facility. The windows were bricked up and its four rooms converted into two insulated rooms, the doors of which said "Zur Desinfektion" ("to disinfection"). It was operational by March 1942. A second brick cottage, the "little white house" or bunker 2, was converted and operational by June 1942.[45] When Himmler visited the camp on 17 and 18 July 1942, he was given a demonstration of a selection of Dutch Jews, a mass killing in a gas chamber in bunker 2, and a tour of the building site of the new IG Farben plant being constructed at the nearby town of Monowitz.[46]

Army photographers and cameramen, along with leading war correspondents, recorded the aftermath of Bergen-Belsen's liberation. This photograph was taken by Sergeant Harry Oakes of the Army Film and Photographic Unit. It shows prisoners sitting by a wire fence which divided two sections of the camp. They are eating their first meal after the liberation of the camp.
Cornelis Suijk—a former director of the Anne Frank Foundation and president of the U.S. Center for Holocaust Education Foundation—announced in 1999 that he was in the possession of five pages that had been removed by Otto Frank from the diary prior to publication; Suijk claimed that Otto Frank gave these pages to him shortly before his death in 1980. The missing diary entries contain critical remarks by Anne Frank about her parents' strained marriage and discuss Frank's lack of affection for her mother.[76] Some controversy ensued when Suijk claimed publishing rights over the five pages; he intended to sell them to raise money for his foundation. The Netherlands Institute for War Documentation, the formal owner of the manuscript, demanded the pages be handed over. In 2000 the Dutch Ministry of Education, Culture and Science agreed to donate US$300,000 to Suijk's foundation, and the pages were returned in 2001. Since then, they have been included in new editions of the diary.[77]
As a result of the Holocaust, the term "concentration camp" carries many of the connotations of "extermination camp" and is sometimes used synonymously. Because of these ominous connotations, the term "concentration camp", originally itself a euphemism, has been replaced by newer terms such as internment camp, resettlement camp, detention facility, etc., regardless of the actual circumstances of the camp, which can vary a great deal.