Answer: An auto-da-fé or auto-de-fé (from Portuguese auto da fé [ˈaw.tu dɐ ˈfɛ], meaning "act of faith") was the ritual of public penance of condemned heretics and apostates that took place when the Spanish Inquisition, Portuguese Inquisition or the Mexican Inquisition had decided their punishment, followed by the carrying out by the civil authorities of the sentences imposed.
The most extreme punishment imposed on those convicted was execution by burning. In popular usage, the term auto-da-fé, the act of public penance, came to mean burning the convicted person at the stake, although that was a punishment for only the most serious offenses.