Vipassana

Vipassanā (Pāli) or vipaśyanā (विपश्यना) in (Sanskrit) means "insight" and is often referred to by Buddhists and non-Buddhists alike as simply "insight meditation". While it is a type of Buddhist meditation as taught by the Buddha, it is essentially non-sectarian in character and has universal application. One need not convert to Buddhism to practice vipassanā meditation. While the meditation practices themselves vary from school to school, the underlying principle is the investigation of phenomena as they manifest in the four Foundations of Mindfulness highlighted in the Satipatthana sutta; namely: Kaya - Body (or breath), Vedana feeling, Citta - Mind, and Dhamma - Mind objects. These phenomena differ from the Khandas — aggregates — because the Citta factor is not connected to any aggregate, as it is the basic mood of the Mind-Body aggregate, while the Dhamma encompasses all mind objects, i.e., the Vinnana, Sanna and Sankhara aggregates, and also all mind objects that are not a fruit of kamma such as, for example, the Four Noble Truths.
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This form of meditation is widely practiced in Theravada Buddhism. Its goal is the realization of the three marks of existence: suffering, impermanence, and "no-soul." It leads to the realization of the true character of Emptiness. Vipassana and Samadhi are considered prerequisites for attaining nirvana by Theravada Buddhism.