The major difference is that the encomienda system was mainly about controlling Indigenous labor and tribute, while the Spanish caste (casta) system was about ranking people by race and ancestry in a social hierarchy.

Encomienda system (labor control)

  • A grant from the Spanish Crown that allowed a Spaniard (encomendero) to demand labor and tribute from specific Indigenous communities.
  • Supposed to protect and Christianize Indigenous people, but in practice often became a form of coerced labor and exploitation.
  • Focused on economic extraction (work in mines, fields, etc.), tied to particular territories and native groups.

Spanish caste system (racial hierarchy)

  • A social and legal classification system that ranked people by their racial ancestry (Spanish, Indigenous, African, and all the “mixed” categories like mestizo, mulatto, etc.).
  • Determined status, rights, taxes, access to education and professions, and general social mobility.
  • Focused on racial classification and status , not directly on assigning labor obligations the way encomiendas did.

Put simply

  • Encomienda = a system of forced Indigenous labor and tribute granted to Spaniards.
  • Casta system = a racial status ladder that sorted everyone in colonial society by ancestry and gave or denied privileges accordingly.

TL;DR: Encomienda dealt with who worked for whom ; the caste system dealt with who ranked above whom in colonial society.

Information gathered from public forums or data available on the internet and portrayed here.