Imagine a big castle in France. The people who live there are called the nobility. They are very special because they come from rich and important families. They have a lot of money and they don't have to do jobs like normal people do.
The nobility have special titles like "duke" or "countess" or "baron". These titles are passed down from one family member to another, like a special nickname. If your dad is a duke, then you will be a duke too when he dies.
The nobility used to be very powerful in France because they had a lot of land and they could make their own laws. They also had special privileges, like not having to pay taxes. But sometimes the common people, who didn't have very much money, got angry with the nobility because they thought they were being treated unfairly.
Eventually, the French Revolution happened and the people got rid of the nobility. They didn't want one group of people to have all the power and special treatment. Nowadays, there are no more French nobles in the official sense, but some people still have those old titles and their families are still considered very important.