Final answer:
An abbey is a monastery or convent of the highest rank, serving as a key religious and communal institution throughout history.
Step-by-step explanation:
A monastery or convent belonging to the highest rank of such institutions is called an abbey. An abbey is a religious community composed of monks or nuns, along with the buildings that house such a community. The head of an abbey is known as an abbot or abbess. Throughout history, abbeys were centers of religious life and also played significant roles in the economic, educational, and social realms. The Rule of Benedict, for instance, was influential in shaping the daily life of monks to include prayer, study, and useful work, thus contributing to a monastery's self-sufficiency and influence.