Medieval Society Structured Around Exchanges

Puzzle 2 of Digital Revolution Easy Pack

Question is: Medieval Society Structured Around Exchanges

and the answer is: FEUDALISM

Word Meaning:

FEUDALISM — A social system based on personal ownership of resources and personal fealty between a suzerain (lord) and a vassal (subject). Defining characteristics are direct ownership of resources, personal loyalty, and a hierarchical social structure reinforced by religion.

Definitions from Wiktionary.