We, human beings, want to get rid of sorrow, suffering and attain true happiness. For this reason, all of us are struggling to earn our own living every day, to get enough food, clothing, and shelter. However, we are never satisfied and contented with what we have. Our desires never come to an end. Consequently, we are certainly to face worry, anxiety, sorrow, pain, grief, lamentation and despair, etc… so if we wish to release from all these sufferings, we need a remedy. This remedy is nothing but meditation (bhāvanā).
Meditation is a method of repeated contemplation on various objects, namely, body (kāya), sensations (vedanā), consciousness (citta) and mental objects (dhamma). There are two kinds of meditation: Samatha (tranquillity meditation) and Vipassanā (Insight meditation). Samatha bhāvanā leads to concentration of mind (samādhi) and Vipassanā bhāvanā leads to wisdom (paññā).
Samatha means tranquility, calm or quietness that makes mental defilements cool. When a yogi fixed the mind on a single object, his mind gradually becomes calm and concentrated. At that time, defilements have no chance to arise and his mind become peaceful and tranquil. At this state, one can temporarily suppress five hindrances, i.e. craving (lobha), hatred (dosa), sloth and torpor (thīna-middha),restlessness (uddhacca) and doubts (vicikiccā) and develop five jhāna factors, namely, initial application (vitakka), sustained application (vicāra) appreciate joy (pīti), bliss (sukha) and one-pointedness of mind (ekaggatā).
Vipassanā literally means Insight or seeing in various ways. In other words, practising Vipassanā means we see things as they truly are. Through persistent practice, we come to see this body and all phenomena are nothing but only mind (nāma) and matter (rūpa). They all are subject to impermanence (anicca), suffering (dukkha) and non-substantiality (anatta). However, most of us misunderstand these and claim impermanent as permanent, suffering as pleasant and non-substantial as substantial. But as for a good Vipassanā yogi, he knows clearly all are the aggregate (khandha) of materiality and mentality and comprehend their real nature.
Vipassanā meditation can be practised in any posture, anytime and anywhere. Of course practice in the meditation centers with experienced masters is always the best. The main point we have to keep in mind is whatever we are doing, walking, etc we have to be mindful or aware of it. By means of vipassanā, one can deeply understand the real nature of mind and matter and gradually eradicate defilements and finally attain Nibbāna.