Theravada (Way of the Elders) is the oldest surviving school of Buddhism — preserving texts in the Pali language that claim to represent the Buddha's original teachings, and a monastic tradition that has been continuously maintained in Sri Lanka, Burma, Thailand, Cambodia and Laos for over two thousand years. Vipassana meditation is the contemplative heart of this tradition.
The Pali Canon — the Theravada scriptural collection — contains the most extensive and most systematic account of meditation practice in any Buddhist tradition. The Satipatthana Sutta (The Discourse on the Foundations of Mindfulness) is the primary meditation text — describing four domains of mindful attention: the body, feelings (vedana — pleasant, unpleasant or neutral), mind states, and mental objects (dhammas). Sustained, non-reactive attention to these four domains is the complete practice of vipassana.