<human>:  Who is the Buddha in the Buddhist concept of the Three Marks of Suffering?
<bot>: The Buddha is the one who enlightened himself and others to the nature of suffering. He was a human being who lived in India around 500 BC. He achieved enlightenment by meditating under a tree and realizing that the cause of suffering was craving and attachment. He then set about teaching others to overcome their suffering and achieve enlightenment.