Vipassanā (Pāli) or vipaśyanā in the Buddhist tradition means insight into the nature of reality. A regular practitioner of Vipassana is known as a Vipassi (vipasya).
In the Theravadin context, this entails insight into the three marks of existence. In Mahayana contexts, it entails insight into what is variously described as sunyata, dharmata, the inseparability of appearance and emptiness, clarity and emptiness, or bliss and emptiness.
Vipassana is one of Asia's most ancient techniques of meditation, attributed to Gautama Buddha. It is a way of self-transformation through self-observation and introspection. In English, vipassanā meditation is often referred to simply as "insight meditation".