it was eventually found to be the most effective means. at the start of operation babrbarossa groups (einzatsgruppen)traveled around behind the German advance shooting mass groups of Jews and Russians (its important to note Germans didnt just kill Jews the war in russia was a war of extermination so that Germans could live on the land) the shooting method was found to be inefective and destressed alot of the men doing it so scientists who had been experimenting on the handicapped devloped a mor effective means the gas chambers.
Jews
Hitler used concentration camps to kill Jew's. who he blamed for the loss of ww1.
Death camps were built to kill prisoners systematically
Concentration camps were used for forced prison labor, while extermination camps were built to kill all prisoners.
neither, they were told to go to villages and generally told exactly how many people they had to kill once they got there.
So that they could kill them.
for the Germans to kill the Jewish
I think it was mainly the Germans who used the concentration camps to kill jewish people and to keep people hostage.
The key disinction is between 'ordinary' concentration camps (such as Dachau or Buchenwald) and extermination camps such as Treblinka and Sobibor. The sole purpose of extermination camps was to kill. Note that Auschwitz and Majdanek combined both kinds of camps.
Everywhere, during his rule, mainly concentration camps
because hitler thought that the people or jews were not of an perfect race so he would send them to concentration camps to maliciosly kill them
yes he did and he burned them in gas showers