What do game cards paper money and mechanical clocks have in common

Serfs- They were imprisoned in the lands of the feudal lords, through obligations in the form of services and taxes and fees. They made up the great majority of the feudal population. Hardly, a servant was able to escape from his condition of life. They were the ones who worked hard for everyone, to support the other two orders (clergy and nobles), since members of the clergy and nobles paid no taxes. They had the protection of their feudal lords and knights.

nobles -  Order made up of feudal lords, the function of the members of this order was to guarantee the protection of society. They concentrated power over land ownership, as well as exercising control over justice (in the case of feudal lords). They lived in castles, with their families, which were true military fortresses.

Clergy merchants - Although the function of this order was to pray, it exercised political, moral and psychological influence in society. By developing religious activities, they could through mass manipulation control the entire society, from the slaves to the highest positions within feudal society. Unfortunately, all this manipulation led people to turn over some of their possessions in the name of Salvation - indulgences. What drove the Catholic Church to have enough power, plenty and land.

Monarchs - to landowners, or fiefs, who held equal or greater power than the monarchs, but were often designated only as a title. They had the protection of the knights.

Artisan - Usually a craftsman would look at a property offering its services in return for the protection and resources available in the feudal property. Not infrequently, the craftsman did not devote all of his available time to craft activities while also being involved in working with the land. In fact, the carriers of this type of ability had a limited radius of action.

The medieval knights were warriors who were part of the nobility. In the Middle Ages (5th to 15th centuries), war was very common and feudal lords and kings needed knights to protect the fief or conquer new lands and riches. The benefit was not to pay taxes.