The encomienda was a legal system that was employed mainly by the Spanish crown during the colonization of the Americas to regulate Native American labor.

In the encomienda, the Spanish crown granted a person a specified number of natives for whom they were to take responsibility. In theory, the receiver of the grant was to protect the natives from warring tribes and to instruct them in the Spanish language and in the Catholic faith: in return they could extract tribute from the natives in the form of labor, gold or other products. In practice, the difference between encomienda and slavery could be minimal. Many natives were forced to do hard labor and subjected to extreme punishment and death if they resisted.

In the former Inca Empire, for example, the system continued the Incaic (and even pre-Incaic) traditions of extracting tribute under the form of labor.

Read more about Encomienda:  History, Encomenderos, Establishment of The Encomienda, Abolition of The Encomienda