The types of jobs vary depending on the type of the concentration camp.
Some prisioners remained inside, doing administration tasks or heavy manual labor.
However, most worked outdoors, working in factories, construction, farms or coal mines, all owned by German companies.
The workers had to walk many kilometres to get to their work places under horrible conditions, and very little food in their systems.
These workers had been previously selected due to their strength and fitness, if they didn't reach the expectations, they were murdered in the crematoriums.

However, the prisoners were overworked, so the life-expectancy in the camps was about 4 months.