A serf was a type of peasant in medieval Europe who was bound to a specific piece of land. Unlike free farmers, serfs could not leave the land without permission from their lord. They worked the fields and provided labor in exchange for protection and a place to live. This system was part of the larger feudal system, where land was owned by nobles and worked by serfs. Serfs had limited rights and were often subject to the demands of their lords. They had to give a portion of their crops and perform various duties. Over time, the decline of feudalism led to the gradual end of serfdom, allowing many to gain freedom and pursue other opportunities.