In the Medievil times, money and heritage were important factors of who you were and what you could do. Read this article about the difference between the nobles and the peasants.
Life for the nobles was very different to the peasants in the middle ages. While nobles enjoyed entertainment and luxuries beyond reason, the peasants had to fight for the basics.
Nobles often had heavily fortified castles or mansions, which were even triple story; peasants had one room houses. Nobles also had grand clothing which would be elegantly covered in jewels while the peasants wore rags. As a noble your only worry was to become a knight for the crusade and settle down, if you were a boy, but the peasants had to work all the time so that their family could have food, shelter and water.
Nobles earned a lot of tithes out of the peasants; so much some peasants had to run out of town. Nobles were expected to protect the land but actually the guards and knights did all that work for them, while they bossed them around. The peasants were the people who were guards to the lord and worked for him. They cooked his food, collected his tax, grew food, got water, made armour and most the peasants knew how to do most of these jobs, yet they eared money not even enough to feed themselves. Lucky peasants like the blacksmiths were given food from the lord as they did not have time to grow it themselves but only labourers like them could be given the “privilege”.
The main privilege that nobles were given that peasants couldn’t have was their limitations. The lord was allowed to do anything. The lord was allowed to decide who marries who, what person does what, what to eat, who to punish; he could also go to other countries, own all the land, have many castles and kill in the forest for sport. If any peasant decides to do one of the things above or not listen to the lord he could have to do extra work or be trailed for treason against his lord.
Even though 80% of the medieval people were peasants, the nobles were unfairly privileged but without the peasants would be nothing.