Single grave culture is a way that people in the past buried their dead. Imagine you have a toy box with lots of toys inside, but you only have one special toy that you love the very most. This special toy is your favorite, and you want to make sure it's treated with extra care, so you put it in its very own box. This is kind of what single grave culture is like.
When people in the past died, their families would often bury them in a special place called a graveyard. This is where lots of people were buried, but sometimes, when someone was really special to their family, they were buried all by themselves in their own special place. This place is called a single grave.
The single grave would usually be marked with something to remember the person by, like a special statue, a big rock or a special branch. This way, it would be easy for their family and friends to find the grave and remember the person who was buried there. Sometimes, the family would also leave special items with the person in the grave, things like important family heirlooms, jewelry or even food and drink that the person enjoyed when they were alive.
This single grave culture happened all around the world and is still done in many places today. It's a way for families to show how much they loved and respected the person who died by giving them their very own special place to rest.