What did Nazis do with captured enemy?

Answer 1

It generally depended on who was involved.

Western European prisoners were treated much better than Eastern European prisoners. Eastern Europeans were most often killed or died of starvation. They were often made into slave laborers.

Of the Western European prisoners, the British & Americans were treated better than the French, Belgian, Dutch or Italian (after Italy surrendered to the Allies) prisoners. Normally British & Americans were not killed or treated as slave laborers. The French, Belgian, Dutch & Italians were often sent to slave labor camps, and starved.

Of the Germans that held prisoners, the SS were the worse offenders against prisoners, and the Luftwaffe (Air Force) treated their prisoners the best.

Also civilian prisoners were treated worse than military prisoners.