What were the responsibilities of peasants in the feudal system?

Peasants grew the crops and tended the livestock. They generally rented strips of land from th elrod of the manor, and paid rent in in the form of labour on the lord's own farm (demesne). Peasants made money by selling their surplus produce. In time, this labour rent was replaced by cash rent, which was more convenient for both lord and peasant. some peasants worked as paid labor on the lord's demesne, or sometimes poor peasants with little or no land of their own worked for wealthier peasants as servants or laborers. 

What does that mean mon