Okay kiddo, so a long time ago in France, there were places called concentration camps. These were places where a lot of people were forced to go and live under really terrible conditions.
The people who were sent to these camps were often different from the other people in France. They might have been Jewish or from other countries, and the people in charge of the camps didn't like them very much.
The people who were sent to the camps had to live in really cramped spaces, and didn't get enough food or water. They were also treated very badly by the people who were in charge of the camps. This was very unfair and cruel.
Thankfully, these concentration camps don't exist in France anymore. It's important to remember the terrible things that happened in the past, so we can make sure they never happen again.