What is the difference between Narayan Bali and Nagbali?

Narayan Bali is an ancestral liberation rite for ancestors who died an unnatural death (snakebite, fire, drowning, suicide). It performs a surrogate funeral using a wheat flour effigy. Nagbali absolves the sin of killing a cobra (Nag Hatya) through a symbolic funeral for the serpent. Narayan Bali can be performed at Prayagraj, Haridwar, and other tirthas. Nagbali is canonically restricted to Trimbakeshwar per Dharma Sindhu and Skandha Purana.