The feudal system is one of the defining elements of the Middle Ages. As my upcoming book, Adventures and Adversities is set in the Middle Ages, have have done a lot of research about the time period. Here is a simple break down of the feudal system.
Had absolute power
Lives in a castle gives lands to the Lords.
Lived in a manor house
Horse riding soldiers and land owners.
Farmed the land rented to them. Also did other work.