How did peasants, serfs (and other non nobility) contribute and benefit economically during the Middle Ages and how did this evolve as times changed?

by panzerkampfwagen
Enrico_Dandolo

Is there anything about this topic that you're particularly interested in? The Middle Ages lasted for nearly 1000 years and you're asking about over 90 percent of the population, especially when you include other non-nobility, which would include inhabitants of towns.