What is "anupubbikatha"

In Theravada Buddhism, anupubbikathā or ānupubbikathā ( Pali) – variously translated as "gradual discourse," "gradual instruction," "progressive instruction," and "step-by-step talk" – is a method by which the Buddha taught the Dhamma to suitably receptive lay people. In this approach, the Four Noble Truths are the consummate teaching. The common formula is:

1. Generosity ( dāna)
2. Virtue ( sīla)
3. Heaven ( sagga)
4. Danger of sensual pleasure ( ādīnava)
5. Renunciation ( nekkhamma)
6. The Four Noble Truths (cattāri ariya- saccāni)