The main feature of the feudal system in medieval Europe was the hierarchical structure of land ownership and obligations between lords and vassals. In this system, lords owned vast estates and granted portions of land (fiefs) to vassals in exchange for military service and loyalty. Vassals, in turn, would oversee the land and manage the peasants (serfs) working it. The feudal system created a rigid social hierarchy, ensuring mutual obligations at each level; noble lords provided protection and land, while vassals and serfs supplied labor and service. This system significantly impacted medieval European society, economy, and politics.