Since 1945-46, the most commonly quoted figure for the total number of Jews killed has been an estimate of approximately six million. This figure, first given at the Nuremberg Tribunal, has been broadly confirmed by later research.

The Holocaust commemoration center, the Yad Vashem Holocaust Martyrs' and Heroes' Remembrance Authority in Jerusalem, comments:

There is no precise figure for the number of Jews killed in the Holocaust. The figure commonly used is the six million established by the Nuremberg Tribunal in 1946 and repeated later by Adolf Eichmann, a senior SS official. Most research confirms that the number of victims was between five and six million. Early calculations range from 5.1 million (Professor Raul Hilberg) to 5.95 million (Jacob Leschinsky). More recent research, by Professor Yisrael Gutman and Dr. Robert Rozett in the Encyclopedia of the Holocaust, estimates the Jewish losses at 5.59-5.86 million, and a study headed by Dr. Wolfgang Benz presents a range from 5.29-6.2 million. The main sources for these statistics are comparisons of prewar censuses with postwar censuses and population estimates. Nazi documentation containing partial data on various deportations and murders is also used. We estimate that Yad Vashem currently has somewhat more than four million names of victims that are accessible.

Raul Hilberg, in the third edition of his ground-breaking three-volume work, The Destruction of the European Jews, estimates that 5.1 million Jews died during the Holocaust. This figure includes "over 800,000" who died from "Ghettoization and general privation"; 1,400,000 who were killed in "Open-air shootings"; and "up to 2,900,000" who perished in camps. Hilberg estimates the death toll in Poland at "up to 3,000,000". Hilberg's numbers are generally considered to be a conservative estimate, as they typically include only those deaths for which some records are available, avoiding statistical adjustment. British historian Martin Gilbert used a similar approach in his "Atlas of the Holocaust", but arrived at a number of 5.75 million Jewish victims, since he estimated higher numbers of Jews killed in Russia and other locations.

One of the most authoritative German scholars of the Holocaust, Wolfgang Benz of the Technical University of Berlin, cites between 5.3 and 6.2 million Jews killed in Dimension des Völkermords (1991), while Yisrael Gutman and Robert Rozett estimate between 5.59 and 5.86 million Jewish victims in the Encyclopaedia of the Holocaust (1990).

There were about 9.4 million Jews in the territories controlled directly or indirectly by the Nazis. (Some uncertainty arises from the lack of knowledge about how many Jews there were in the Soviet Union). The 6 million killed in the Holocaust thus represent about 64% of these Jews. Of Poland's 3.3 million Jews, over 90 percent were killed. The same proportion were killed in Latvia and Lithuania, but most of Estonia's Jews were evacuated in time. In Czechoslovakia, Greece, the Netherlands and Yugoslavia, over 70 percent were killed. More than 50 percent were killed in Belgium, Hungary and Romania. It is likely that a similar proportion were killed in Belarus and Ukraine, but these figures are less certain. Countries with notably lower proportions of deaths include Bulgaria, Denmark, France, Italy and Norway. Finally, of the 750,000 Jews in Germany and Austria in 1933, only about a quarter survived. Although many German Jews emigrated before 1939, the majority of these fled to Czechoslovakia, France or the Netherlands, from where they were later deported to their deaths.

The number of people killed at the major extermination camps is estimated as follows:

Auschwitz-Birkenau: 1.4 million; Belzec: 500,000; Chelmno: 152,000; Majdanek: 78,000; Maly Trostinets: 65,000; Sobibór: 250,000; and Treblinka: 870,000.

This gives a total of over 3.3 million; of these, 90% are estimated to have been Jews. These seven camps alone thus accounted for half the total number of Jews killed in the entire Nazi Holocaust. Virtually the entire Jewish population of Poland died in these camps.

In addition to those who died in the above extermination camps, at least half a million Jews died in other camps, including the major concentration camps in Germany. These were not extermination camps, but had large numbers of Jewish prisoners at various times, particularly in the last year of the war as the Nazis withdrew from Poland. About a million people died in these camps, and although the proportion of Jews is not known with certainty, it was estimated to be at least 50 percent. Another 800,000 to 1 million Jews were killed by the Einsatzgruppen in the occupied Soviet territories (an approximate figure, since the Einsatzgruppen killings were frequently undocumented). Many more died through execution or of disease and malnutrition in the ghettos of Poland, Belarus, Ukraine, Lithuania, Latvia and Hungary before they could be deported.

About 1,500. This staggering figure includes all satellite camps, including temporary camps. There were about 20 main camps (Stammlager).

Most concentration camps had many sub-camps, many of them labour camps that only functioned for a short time. The list below from the German-language Wikipedia is very good. There is a link below to the list issued by the Federal German Ministry of Justice. This can be assumed to be more or less definitive.

(The figure of 1,500 only includes camps run by the SS and related organization. It does not include camps for Soviet prisoners of war or camps for forced labourers imported to Germany from Eastern Europe).

Please see the link for the full list and also the related question.

Wikipedia and other sources name six extermination camps, all located in occupied Poland:

• Auschwitz II (part only)
• Belzec
• Chelmno
• Majdanek (part only)
• Sobibór
• Treblinka II

These six were killing centres and enjoy a kind of canonical status. Many would add Maly Trostenets in Belarus and some include Janowska in Ukraine.

The figure of 1,500 camps does not include camps for forced foreign labourers sent to Germany from the various countries under German rule. Many of these camps, especially those for Poles and Ukrainians, were little better than concentration camps. Nor does the figure include regular POW (prisoner of war) camps.

Note that there were three grades of ordinary Nazi concentration camps. These were, in ascending order of harshness: Grade I (such as Dachau) , Grade II (such as Buchenwald) and Grade III (such as Auschwitz III - aka Buna or Monowitz). Conditions at the Grade III camps were appallingly bad.

In 1944 there were 5.7 million forced foreign workers in Germany, many of whom had been abducted (kidnapped), taken to Germany and forced to work there.

Please see the link beginning with the word Bundesministerium for the full list.

Because the camps were located in all of the occupied countries in some form or another, and because many camps had sub-camps and even the sub-camps were further divided at different labor sites, I doubt that even the Nazi's could answer. Camps existed in Africa and even in the British Channel Islands. Not all camps were giant extermination factories, some were collection and transit points while the vast majority were labor centers with as few as a couple dozen inmates.

" Jewish Virtual Library estimates that the number of Nazi camps was closer to 15,000 in all of occupied Europe"

[From http://en.wikipedia.org/wiki/Nazi_concentration_camps ]

But even that is an estimate: it's worse than that:-

"THIRTEEN years ago, researchers at the United States Holocaust Memorial Museum began the grim task of documenting all the ghettos, slave labor sites, concentration camps and killing factories that the Nazis set up throughout Europe.

What they have found so far has shocked even scholars steeped in the history of the Holocaust.

The researchers have cataloged some 42,500 Nazi ghettos and camps throughout Europe, spanning German-controlled areas from France to Russia and Germany itself, during Hitler's reign of brutality from 1933 to 1945.

The figure is so staggering that even fellow Holocaust scholars had to make sure they had heard it correctly when the lead researchers previewed their findings at an academic forum.....

When the research began in 2000, Dr. Megargee said he expected to find perhaps 7,000 Nazi camps and ghettos, based on postwar estimates. But the numbers kept climbing - first to 11,500, then 20,000, then 30,000, and now 42,500.

The numbers astound: 30,000 slave labor camps; 1,150 Jewish ghettos; 980 concentration camps; 1,000 prisoner-of-war camps; 500 brothels filled with sex slaves; and thousands of other camps used for euthanizing the elderly and infirm, performing forced abortions, "Germanizing" prisoners or transporting victims to killing centers.

In Berlin alone, researchers have documented some 3,000 camps and so-called Jew houses, while Hamburg held 1,300 sites.

Dr. Dean, a co-researcher, said the findings left no doubt in his mind that many German citizens, despite the frequent claims of ignorance after the war, must have known about the widespread existence of the Nazi camps at the time.

"You literally could not go anywhere in Germany without running into forced labor camps, P.O.W. camps, concentration camps," he said. "They were everywhere."

[From article "The Holocaust Just Got More Shocking' at http://www.nytimes.com/2013/03/03/sunday-review/the-holocaust-just-got-more-shocking.html?pagewanted=all&_r=0 ]

'
35 main and 100's of smaller
There were about 35 main and 1000 smaller concentration camps during World War 2 and there were 6 extermination (death) camps.

There were different kinds of camps, and the function of the older camps changed over time.

Some short, simplified answers:

• Initially, the camps were used to terrorize opponents of the Nazi regime.
• Later, (from about 1938-39 on), they provided slave labour.
• From late 1941 on, extermination camps were set up as mass killing facilities for the 'Final Solution'.

The progression of Nazi camps:

1. The first concentration camps were set up in 1933. They were punishment camps set up in order to terrorizeopponents of the Nazi regime. They soon became notorious for horrific brutality. In addition to genuine opponents, some other people were also sent there; for example, people who had offended local Nazi party bosses and so on. Since the purpose of these camps was to terrorize would-be opponents of the regime, information about what went on there was allowed to get out. Most of the camps established in the early months were temporary and were closed down within a few months. However, Dachau remained. The existence of these camps was not secret, though the precise details of what went on were 'hush-hush'. In fact, Himmler launched Dachau amid considerable publicity.
2. In the late 1930s a section of the SS set itself up as a business entreprise. It was at this stage that the systematic use of prisoners as slave labour on loan to business began.
3. Following the 'Night of the Broken Glass' (9-10 November 1938) about 30,000 Jews were sent to concentration camps. By Christmas 1938, two thousand of them were dead. The main purpose was to bully them into leaving Germany.
4. The Nazi invasion of Poland meant that the Nazis made what they called their 'Jewish problem' much bigger. They also had to deal with the Polish resistance. Initially, Jews were herded into ghettos, which were sealed off from the surrounding areas.
5. In 1940 the first big concentration camp in Poland - Auschwitz - was established, initially as an exceptionally harsh forced labour camp for uncooperative Poles and members of the Polish intelligentsia and resistance.
6. From late 1941 onwards, extermination camps ('death camps') were set up, mainly in Poland. These were intended solely for the extermination of the Jews and Romanies (gypsies). Most of the extermination camps were small: the aim was to kill newly arrived prisoners within 24-48 hours. This was 'assembly line' murder.
7. Several transit camps were established, which held prisoners till they could be transferred to concentration camps or extermination camps. However, a few prisoners were kept in transit camps for years.
8. As the Soviet Army drew close to the camps in Poland some of the inmates were transferred to camps in Germany. For example, Anne and Margot Frank were moved from Auschwitz Women's Camp to Bergen-Belsen, and Elie Wiesel was transferred from Auschwitz III (Monowitz) to Buchenwald.
9. In addition to the concentration camps (run by the SS), there were several labour camps run by a variety of organizations. Civilians from various Nazi-occupied territories (including Poland and Ukraine) were in effect kidnapped and sent to Germany as very cheap labour. Conditions in these camps varied but were never good. In some cases the inmates were paid in vouchers, some of which could be sent home.

Cinematic references include Schindler's List (1993), The Pianist (2002), and Red Dawn (1984).

Recommended reading:

1. Elie Wiesel, Night
2. Eugen Kogon, The Theory and Practise of Hell

Please also see the related questions.

Sometimes the terms concentration camp and extermination (or death) camp are, misleadingly, used interchangeably. The sole purpose of extermination camps (death camps) was to kill (usually by gassing).

Most larger concentration camps had several satellite or sub-camps. There were also several small, temporary concentration camps. If one includes all these as well as transit camps and the small number of specialized camps (for example for unruly children), the Nazis ran a total of nearly 1,500 concentration camps in Germany and German-occupied countries. (It is not possible to list them all here, but under the answer there is a link to a full list). For these purposes a concentration camp is a one run by the SS (or in 1933-34) the SA.

Concentration camps were:

1. Punishment and deterrent camps (for example, for Communists, socialists, liberals and other political opponents of the Nazi regime, later also for 'antisocial elements' and homosexuals).
2. Forced labour camps, where many Jews and others were worked to death on grossly inadequate food.
3. For resistance members.

• The first permanent concentration camp was Dachau, located near Munich (22 March 1933).
• Oranienburg, near Berlin, opened the day after Dachau.
• Sachsenhausen (near Berlin)
• Buchenwald is also located in Germany, near Weimar.
• Ravensbrueck (women's camp), North Germany.
• Mauthausen-Gusen (Austria)
• Neuengamme, near Hamburg.
• Flossenbuerg in Bavaria, near the Czech border.
• Bergen-Belsen near Hanover.
• Dora-Mittelbau (originally a satellite camp of Buchenwald)
• Stutthof (near Danzig)
• Gross Rosen
• Plaszow (near Krakow)
• Natzweiler (Alsace)

In addition, there were transit camps, where prisoners were held till they could be sent elsewhere.

• Auschwitz-Birkenau (= Auschwitz II - part only)
• Belzec
• Chelmno
• Majdanek (part only: it was used as a 'back-up' facility when other camps were killing at full capacity. The role of this camp is being looked at again by some Holocaust historians)
• Sobibor
• Treblinka II

These extermination camps were all in Poland.

In addition, Maly Trostenets (near Minsk, Belarus) and Bronnaya Gora (also in Belarus) were extermination camps, but they are not well known as there are no known survivors.

The Auschwitz group of camps and Majdanek were 'dual purpose' camps: they had sections that functioned as extremely brutal hard labour camps, and also a section that was an extermination (death camp). In fact, Auschwitz-Birkenau (also called Auschwitz II) was the largest death camp of all.

The death toll in 'ordinary' concentration camps was high, but over 80% of the inmates of Dachau (a concentration camp) emerged alive; however, Belzec (an extermination camp where 434,500 Jews and an unknown number of Roma and others were gassed) had only two(!) known survivors. There was a real difference.

The number of 'ordinary' camps main camps was about 24. If one includes all the satellite camps and temporary camps, the total was a staggering 1,500 camps. (There is a link below, giving the full list compiled by the Federal German Ministry of Justice. Many of them are not well known in Western Europe and the U.S. However, the last column gives the main camp (or Stammlager) to which the various smaller camps were attached).

In addition, there were transit and collection camps, where people were held temporarily until the SS had a train load of victims to send on to other camps. There were also a few camps for 'unruly' and 'difficult' children aged 12+ (later 8+).

Note the German Wikipedia list (click link below), which is very thorough and includes the early camps, many of which were shut down later, such as Columbia-Haus, Berlin. In addition, in 1967 the Federal German Ministry of Justice compiled a list of all concentration camps - and the total comes to about 1,500. (See link below).

Towards the end of the war conditions in most concentration camps deteriorated sharply.

Have a look at Martin Gilbert's Atlas of the Holocaust.

Please see the related questions.
The name of concentration camps were Auschwitz.

There is a widely held, but mistaken view that the Nazis made extensive use of fiendishly ingenious torture devices. In concentration camps the guards most commonly beat inmates - sometimes with their fists and sometimes with various implements ranging from whips to cudgels and long, heavy crowbars.

Sometimes the guards pushed prisoners to the ground and kicked them black and blue with their heavy jackboots (which were a bit like heavy 'goth' boots), smashed their teeth, and so on.

However, actual torture differed from camp to camp. Mengele, the "Angel of Death", did indeed commit vile experiments on select inmates -- with a particular fixation on identical twins, dwarfs, and genetically inferior persons. These experiments included: -Hurting a twin and gauging the other twins' reaction -Removing body parts to test the survival time of the patient -Testing new, unfounded surgery techniques (supposedly without anasthesia -- debated by some historians) -Using saltwater and electricity to gauge the pain response of the human body These means did became the most infamous torture techniques in the Nazi regime.

However, general torture of the inmates is pretty much easy to imagine -- whipping; random killing or maiming; rape; defamation and degradation of the person's rights; many torture techniques that the Nazi prison guards (and even some prison inmates who themselves practised torture) can be found in modern day camps. Some of the SS men did a little reading on the Inquisition ... Bullies are seldom original. However, they didn't have time for elaborate 'torture devices'.

At Auschwitz they sometimes unleashed hungry dogs on the prisoners.

One of the more common tortures used in some Nazi camps involved tying an inmate's wrists securely behind the back and them suspending him (or her) for anything from 30 minutes to a few hours. The pain and the effect on the muscles and joints can easily be imagined. It was horrific.

An interesting early account of life in a concentration camp is: Eugen Kogon, The Theory and Practice of Hell. (Various publishers). Eugen Kogon was a prisoner at Buchenwald from 1939 till the camp was liberated in 1945. He was immensely resilient and wrote most of the book in 1945-46. Part of it was used in evidence by the prosecution at Nuremberg.

As Jean Amery (anagram and pen-name of Hans Mayer) observed, there was a fundamental sense in which torture - a sadistic and fundamental attack on the whole person - lay at the very heart of Nazism, with its bottomless contempt for civilization, morality and human life.

As many as two-thirds of Europe's Jews were killed during the Holocaust. Other groups, such as gypsies, the mentally disabled, and the handicapped were also killed. Many victims were killed in mass, open air shooting, especially in the then Soviet Union (Russia, Ukraine, Belarus) and were not sent to camps.

-----------------

The proportion varied considerably. At the extermination camps (Auschwitz-Birkenau, Chelmno, Treblinka II, Majdanek ('new section'), Belzec and Sobibor very few survived. At these camps most victims were gassed soon after arrival. A handful of Jews at these camps were forced to help in various ways with the extermination process, for example, by dragging the corpses to the crematoria or mass graves. Some of these survived. However, there are only two(!) known survivors from Belzec, where according to the SS's records, 434,508 Jews plus an unspecified number of Roma were killed.

At Dachau, which was mainly a camp for political opponents of the Nazis, an estimated 25,600 died out of 150,000.

The word "survived" needs defining carefully, otherwise one ends up talking about quite different groups of people. The usual meaning of the expression "a holocaust survivor" is someone who was sent to an extermination (death) camp, concentration camp (or equivalent), but was still alive at the end of WWII in Europe or when the camp was liberated. (In other words, Jews and others who had managed to flee to countries like the U.S., Britain and Sweden before the start of World War 2 are not included). The most common figure is about 200,000. Jews in hiding who survived also count as survivors.

Incidentally, the criterion 'left the camps alive' is trickier than one might think. Some Jews were moved from one camp to another. Anne and Margot Frank, for example, were moved on 30 October 1944 from Auschwitz to Bergen-Belsen. So they were alive when they left Auschwitz, but died of typhus at Bergen-Belsen in March 1945.

Once one was actually in an extermination camp system the chances of survival were remote. It needs to be noted that there were different types of camps, ranging from 'punishment camps' like Dachau to extermination camps. From 1939-40 onwards the SS graded the camps into three types, I, II and III and later added the extermination camps. There was not much difference between types I and II, except that the prisoners were usually better fed at a camps graded I. At grade III camps most prisoners had to do very hard manual labour on grossly insufficient food and were worked to death. At the extermination camps, nearly all the prisoners were shot or gassed soon after arrival. For information: Dachau was a grade I camp, Buchenwald was grade II, Auschwitz I (old section) was grade III, while Treblinka, the Birkenau section of Auschwitz, Belzec, Sobibor, Chelmno and the newer part of Majdanek were extermination camps. Obviously, one's chances of survival at Dachau were much better than, for example, at Treblinka.

--------------

More recently, some who feel that other groups of Nazi victims have been overlooked, have extended the term to cover the overall slaughter committed by the Nazis of victims on the basis of group membership. However, among historians the term the Holocaust (as a proper noun) is generally used only of the genocide of the Jews. (See the Wikipedia article on the the Holocaust for more information).

There are, however, competing definitions. Please see the related question.

Most professional historians use the term specifically for the Nazi genocide of the Jews. For example Richard J. Evans, Regius Professor of Modern History at Cambridge, writes as follows:

The standard work by the distinguished Canadian historian Michael Marrus, TheHolocaust in History, focused on, to use his own words, 'the Holocaust, the systematic mass murder of European Jewry by the Nazis'. Similarly, Sir Martin Gilbert, in his documentary compilation, The Holocaust: The Jewish Tragedy( London, 1986), concurred in referring to 'the systematic attempt to destroy all European Jewry - an attempt now known as the Holocaust'. Another author, Ronnie S. Landau, put forward a similar definition in his book, The Nazi Holocaust: 'The Holocaust involved the deliberate, systematic murder of approximately 6 million Jews in Nazi-dominated Europe between 1941 and 1945.'

Richard J. Evans, Telling Lies About Hitler: The Holocaust, History and the David Irving Trial, Verso, London and New York, 2002, pp. 113-4.

Hitler began the persecution of Jews in 1933. Also, in 1945 survivors of Death Camps had a nation to go home to, except the Jews. In 1945-46 some Jews returning home in Poland were killed in pogroms, for example at Kielce. Many of those not killed fled to Palestine, helping to create the state of Israel in 1948.

The term holocaust as applied to the extermination of the Jews during WWII is recent in origin, acquiring that meaning after movies like 'Schindler's List' came out. Certainly the number of non-Jewish civilians and POWs exterminated during WWII was probably as great as the number of Jews exterminated. In the U.S., the great injustices and killing has been told by Jewish writers, editors, and moviemakers.

Firstly, the term "holocaust" (or as Jews call it: Shoah) was adopted to replace the term "Final Solution" which was the Nazis' own euphemism for the systematic extermination of the Jews. The term holocaust (usually written with a small h-) is now often used to describe other genocides such as that of 5-7million Ukrainians by Stalin and 1.2-1.5 million Armenians by the Ottoman Turks.

Sadly, movie makers in the United States often overlook the fate of non-Jewish victims of the Holocaust. Although horrific and we should never forget, it seems a week doesn't go by that a Holocaust program isn't shown on TV or in the newspapers. Contemporary Germans feel tremendous guilt due to this barrage of media even though they weren't even born in this era.

Shoa , also spelled Shoah and Sho'ah, Hebrew for "Calamity", is the Hebrew term for the Holocaust. It is used by many Jews and a growing number of others due to theological discomfort with the literal meaning of the word Holocaust; these groups believe it is theologically offensive to imply that the Jews of Europe were a sacrifice to God. It is nonetheless recognized that most people who use the term Holocaust do not intend such a meaning. Similarly, many Roma (Gypsy) people use the word Porajmos, meaning "Devouring", to describe the Nazi attempt to exterminate that group.

As we all know Jews were going to be killed, none of them were meant to survive, and that may be why people say it is Jews' Holocaust. But, as I think about it, if Hitler would finish with Jews before the end of the war, Poles were next. What is more, there was already great number of Poles who died along with Jews that if not close to the number of Jews killed, probably is the same or even greater. I think that saying it was only the Jew's Holocaust is just a wrong interpretation of the history.

Communists, socialists, liberal intellectuals, a few Church figures, trade unionists, Gypsies, physically and mentally disabled all fell victim to the Nazis also.

The very first target of the Nazis was not so much the Jews, or any single religion or ethnic group for that matter. Once Hitler seized power he gave his brownshirts the go-ahead to attack the Communists and Social Democrats (who were in fact the Nazis' arch enemy). The Reichstag fire was used in order to make the Communist Party illegal in Germany.

What does it MATTER if it was 5.69 Million? It was people killing people, for the simple reason, that they were different in some [minor] way. No point arguing about Numbers. I was born in Germany in 1941, and believed all the stories about how 'the 'Jews lived off the backs of the German public. I believed the films that the Nazis showed of the 'Happy Jewish Families' out in the East, in very nice 'rest camps'.. I did not know, that after the films were made, all those people, died! I, and all the 'grown ups' believed the Films, BECAUSE WE WANTED TO! The rumours we all heard, were too horrible to believe. We were all guilty, even I as a baby, for we believed!! And that, as well as the destroyed families, made us all Victims of a system. Yes, even the Ordinary German , was a Victim, and don't forget, the Camps were at FIRST built to deal with Germans who said the wrong things to the wrong people, even their own children. Millions died in these Camps, some were also German. Just one life lost, is a tragedy. So forget about numbers, and just make sure it cannot happen again....Though I will not hold my breath!

Further points

There is an increasing tendency to acknowledge other victims of the Holocaust. It would be unfortunate if there were an unseemly quarrel about 'ownership' of, for example, Holocaust Memorial Day. However, surely every group is entitled to its own remembrance of what happened.

The first permanent Nazi oncentration camp was in Dachau, near Munich, and was opened on 22 March 1933. It was officially launched at a press conference by Himmler on 22 March 1933. He said that the camp was for 'enemies of Germany'. Oranienburg (near Berlin) opened the next day. Some temporary, concentration camps were set up a few days earlier but closed within months.

It was intended mainly for political opponents - in order to terrorize them, not specifically for Jews.

See link below for more detail.