During WWII, the Nazis designed camps with the specific intent of exterminating the entire Jewish population. The first of the dedicated extermination camps to begin operation was Auschwitz Birkenau in September 1941. From 1933 (Hitler's first year in power) concentration camps had been set up in which many Jews had already died.
Ermdeviation was uncertain that the Holocaust took place because he had read there is no evidence of human remains at the sites of the extermination camps. However, the evidence is out there and is insurmountable - one must simply note the six million Jews that "disappeared" from Europe during the Holocaust, the photographic and video evidence from the concentration camps, the documents relating to the concentration camps, the admissions at the Nuremberg Trials relating to the Holocaust, the physical remains of the camps, the stories of the prisoners, employees, and officers of the camps, etc. My own step gran's father was a cleaner (that's what my step gran says at least) at Sachsenhausen concentration camp where around 100,000 people died. She admits what was done to the Jews was "very bad" - clearly not acknowledging the scale of horror.
Regarding ermdeviation's specific request that evidence be put forward proving that human remains were found as the sites of the extermination camps, here is one particular source:
If you have any points you would like to make about the Holocaust or questions you would like to ask, please post them in this thread.