Vipassanā is a Pali term often translated as "clear-seeing" or "insight", but which is most commonly used to refer to a specific type of meditation known as "insight practice"; through seeing the true nature of all sensations clearly and with precision, a practitioner can gradually remove the veil of ignorance, (Pali://avijjā) itself the cause of fundamental suffering.
The basic technique itself involves bare attention to the moment-by-moment sensate experience of reality, but the specifics of the approach and way in which it's presented differ depending on tradition.
In Theravada, emphasis is placed on experiential observation of The Three Characteristics, as well as the Four Noble Truths so that a yogi may come to understand directly how all phenomena are subject to change, devoid of self, and inherently unsatisfactory.
Vipassana is practiced in many ways, but the "noting" technique developed by Mahasi Sayadaw is by far the most common method practiced on The Dharma Overground. Some other methods include body-scanning as taught by S.N. Goenka; observation of the Four Foundations of Mindfulness; bare sensate attentiveness.
While also utilizing some of the same methods as the Theravadan traditions, Mahayana introduces the "Two Truths Doctrine" and the concept of Śūnyatā, or Emptiness.
Mahamudra & Dzogchen
Effected by many practices, including: