The Vinaya Pitaka mainly deals with the Disciplinary code of the order
of monks(Bhikkhus) and nuns (Bhikkhunis) it describes in detail the
gradual development of the Sasana (Dispensation) it also give and
account of the life and ministry of the Buddha. Indirectly it reveals
some useful information about ancient history, Indian customs art,
sciences, etc.
For nearly twenty years since his enlightenment, the Buddha did not lay
down rules for the control of the Sangha. Later, as the occasion arose
and the number of monks increased, the Buddha promulgated rules for the
futur discipline of the Sangha.