How did the nazis go about exterminating the approximately 11 million people who died in the holocaust?

Hitler started off with gettos with little food and supplies and he said it was too slow he made death camps such as aushwitz killing people with zyklon gas and burning the bodies in the oven if you were lucky they would make you work some died when they got lined up and shot after digging their own graves some died on trains they took Jews to other camps

They live in a demilitarized border