The Spanish had a significant advantage over the native peoples in terms of military technology. They had access to guns, cannons, and other weapons that were far more powerful than anything the natives had. This allowed them to defeat the natives in battle and establish their control over the New World.
In addition to their military superiority, the Spanish also benefited from the fact that the native peoples were often divided and disunited. This made it easier for the Spanish to conquer them, as they were able to take advantage of rivalries and alliances between different native groups.
Finally, the Spanish were also able to benefit from the spread of disease among the native peoples. Diseases such as smallpox and measles devastated the native populations, making it even easier for the Spanish to conquer them.