The term concentration camp is a broad one. Several categories of camps are part of this definition: labour camps, transit camps, immigrant detention or re-education camps, for some people even the extermination camps. A common thing among these camps is that the people in it are usually detained without hearing or defined sentence. The nazi concentration camps can be roughly divided into 3 groups: pre-war re-education camps in greater Germany, the transit camp in western Europe and the labour camps in eastern Germany. Pre-war re-education camps gradually turned into labour camps during the war.