So, the Roman Curia is like a big group of people who help the Pope run the Catholic Church. Some of these people have special jobs called "hereditary officers" which means they get to keep their job in their family, like a family heirloom.
For example, let's say a man named Mr. Smith is a hereditary officer and his job is to help organize important meetings. His son, when he grows up, can also have the same job as his dad if he wants to, because it runs in the family.
This isn't like other jobs where you have to apply and interview to get it. It's passed on from parent to child like a family tradition.