A family from Ancient Egypt
Inheritance means that when your parents die, you get whatever stuff they owned, especially their house and their farm, if they had one. This was very important in ancient and medieval times, because it was hard to get land any other way, and most people wanted to be farmers.
There were two main systems of rules for inheritance in ancient and medieval times. According to one system, when your father died, all of the sons (you and your brothers) inherited equal parts - you split up the farm between you. This had the advantage of being fair (except to your sisters!), but it meant that each of you only got a little tiny piece of land.
People used this system in ancient West Asia, and in ancient Rome. In ancient Egypt, both your brothers and your sisters got equal shares. Islamic law also gave sisters a share, but only half as much as their brothers got.
According to the other system, when your father died, the oldest son (your oldest brother) got all of the land, and the other brothers and sisters got nothing at all. This was not fair, but at least one of you got a good-sized farm. Younger sons had to find some other way to support themselves, like becoming a monk or fighting in the army.
People used this system in ancient China - Confucius said that the oldest son should get everything - and in ancient Israel. In the Bible, Jacob decides to leave most of his property to his son Joseph, instead of dividing it equally between Joseph and his brothers (Genesis 28). This was also the system in medieval France and England.