Einsatzgruppen was a group of bad people who did very bad things during World War II. These bad people were specially trained soldiers who were sent by the German government to invade other countries and kill people who they thought were not good enough or not wanted by their government.
They would go to these countries and gather together all the people they did not like, such as Jews, Gypsies, homosexuals, disabled people, and political prisoners. They would then line them up in front of big holes in the ground and shoot them all with guns. This was called a mass shooting. They did this over and over again until they killed many thousands of people.
These bad people did not care about how these people felt or that they had families who loved them. They did not think that they were doing anything wrong, and they thought that they were helping their country by getting rid of these people. But what they did was very, very wrong, and it is important that we remember and learn about the atrocities that were committed so that we may do our best to prevent them from happening again.