The king during the fuedal system ruled a large area of land and he distributes this land among the lords. In return vassals promised to defend the king's land from invaders.Regarding his responsibilities, the king had to make sure his city and land were safe
In the time of Feudalism, the Church and clergymen were considered very influential and the jobs of Bishops, priests, and clergies were considered very noble.
The Nobles of the Middle Ages were very wealthy and lived in luxury. Their most important responsibility was to stay loyal to the monarch and keep by their side for assistance in the time of military need or miscellaneous services. Though they never engaged in manual labor. Noblemen and women received many rights to amenities for their jobs.
The serfs and servants were the working and lowest class of the feudal system. These serfs were often mistreated because they considered in servitude which is why this system of govt is unfair because it puts excess pressure on one class.
Serfs engaged in heavy labor and did all farm work. Some of their responsibilities were to raise livestock, build and care for buildings, made clothing, cut wood, etc. They received nothing for their work and did not have any rights to do anything that they wanted.
Vassals were responsible for the land appointed to them by the king. These land were called FIEFS and they usually also pay allegiance to their king. Each revived their own manor to live in on their fief as well. It was their job to protect their land and they were usually knights but did not have to be. Sometimes knights were vassals but also did not have to be.