Serfs were treated like slaves in parts of medieval Europe with the major exception that:

Question

Quizplus · Accepted Answer

While serfs were treated similarly to slaves in some regards, such as being tied to the land they worked and at the mercy of their lords, they could not be sold apart from their historic lands. This meant that even though they were not entirely free, they had some rights to the land they worked on and could not be bought and sold as commodities like slaves.

Serfs Were Treated Like Slaves in Parts of Medieval Europe