In doing so, Raul Hilberg identified four Phases of the Holocaust, that ease understanding the whole process.
Before the Nazis could actually make laws that discriminate Jews a law needed to be made identifying the range of persons to be targeted by those measures. This was especially hard, since the Nazi ideology saw the Jews as a race, and not a religious community.
Laws of that time identified someone with 3 or more Jewish grandparents as 'full Jew', some with 2 Jewish grandparents as a '1st degree hybrid', and someone with one Jewish grandparent as '2nd degree hybrid'. The actual confession of the person itself wasn't taken in consideration, and so many converted Jews were now declared to be Jews by the state.
'2nd degree hybrids' and Jews married to Aryans (people with mostly or only German or Scandinavian ancestors) were sometimes exempted from extermination.
After defining the term Jew in law, the Jews were discriminated by such measures as putting a big J in their passports, food ration stamps, or, after 1941, making them wear the star of David all the time clearly visible on their clothes.
After defining the term Jew, Jewish people as doctors, lawyers or even housemaids were no more allowed to work for Germans, and Jews no longer were allowed to employ Germans of certain professions. Neither were they allowed to be on the boards of firms or to hold shares of a firm. Firms, houses, etc. in Jewish possession were 'arianized', which meant, that they were sold to an Aryan. Usually there was blackmail involved, and the German state and the involved Aryans made huge profits in this transactions, while the Jewish business people were forced to agree to the transactions.
After the Jews were segregated by definition from the rest of the people, and their economic ties with the rest of the society were mostly cut or restricted, the Jews were physically separated from the rest of the society. Either by forcing them to move to special houses, or to ghettos, Jews now had to live in inferior conditions.
By concentrating the Jews into ghettos, concentration camps or forced-labor camps, the Jews were completely cut off from the rest of society, dependent on the goodwill of and under the control of the Nazis. The Nazis controlled, how much food entered the ghetto, used the ghetto populace as cheap work pool, etc.
Put outside society, without money, and under the control of the Nazis, the Jews now where defenseless.
In 1942, after the Wannsee conference, the Nazis began to murder the Jews in large numbers. Extermination squads were already conducting mass shootings of Jews in the areas of the occupied Soviet territories since 1941, and now Jews were either deported to then-empty ghettos like that of Riga to be shot later, or to the death camps of Operation Reinhard: Treblinka, Belzec and Sobibor. Polish Jews living in the formerly Polish territories then integrated into Germany were killed in Chelmno (Kulmhof) in mobile gas chambers. Later on starting 1943 Jews were deported to Auschwitz-Birkenau, the most well-known death camp.Identification / Definition
Economic Discrimination and Separation
Concentration
Extermination