The social classes were:
Peninsulares: These were people born in Spain, living in Latin America. They were a tiny minority, but occupied most positions of power, including the viceroyalties.
Criollos: These were people of Spanish descent born in Latin America. They also occupied many positions of power, and formed the rest of the Upper class. Most of the leaders of the Latin American Revolutions belonged to this social class.
Mestizos: mestizos were the majority of the population of most of Latin America. They were people of mixed Spanish and Native American descent, and had diverse occupations like farmers, artisans, laborers, and even priests.
Native Americans: natives were below mestizos in social rank, and most lived in reservations were they had to work for their Spanish or criollos overlords.
Slaves: slaves were Black people imported from Africa who were at the bottom of the social hierarchy. They had no freedom, no civil liberties, could be bought and sold as property, had very low life expectancy, and were subjected to harsh working conditions and brutal treatment.