Ignorance is the fundamental misapprehension of reality that underlies suffering in Buddhist thought. Ignorance refers to a deep misunderstanding of the nature of phenomena, especially impermanence, nonself, and dependent origination. It is identified as the root of the three poisons and the starting point of the chain of dependent origination, giving rise to craving, attachment, and the cycle of rebirth. Overcoming ignorance through wisdom is central to liberation.