What is chattel slavery

Chattel slavery is the kind of slavery that we know from the history of the US: when a person has an absolute power over another person's life, when this person belongs to another person "legally" or officially in some sense.

The slavery which is not chattel slavery is for example when a person for whatever reason is not free to terminate the contract but can for example move freely after working time and does not "oficially" belong to another person.