In Theravada Buddhism, the process of liberation involves a threefold training: sila or morality, samadhi or concentration and panna or wisdom. Pursuit of this training leads to the abandonment or uprooting of the three unwholesome roots and, when this is accomplished, to nibbana or enlightenment.
This threefold training is a summary form of the Noble Eightfold Path. In the Noble Eightfold Path, the morality training is represented by right speech, right action and right livelihood. The concentration training is represented by right effort, right mindfulness and right concentration. The wisdom training is represented by right intention and right view. The practice associated with morality is observance of the appropriate precepts for one's station in life (layman or monastic) and the cultivation of virtues. The practice associated with concentration is meditation, and the practice associated with wisdom is insight.
From this it is clear that sila is the primary training and the foundation for training in meditation and insight.