NAMO SAKYAMUNI BUDDHA
The Vinaya-pitaka is one of the Tripitaka. The Vinaya-pitaka are the rules and regulations of the Order of Bhikkhus and Bhikkhunis.
For nearly twenty years after the enlightenment of the Buddha, no definite rules were laid down for the control and discipline of the Sangha. Subsequently as occasion arose, the Buddha promulgated rules for the future discipline of the Sangha.
Vinaya Pitaka mentions in details (fully describes) reasons for the promulgation of rules, their various implications, and specific Vinaya ceremonies of the Sangha
The Vinaya Pitaka consists of five books:
+ Parajika (skt)—Major offences.
+ Pacittiya (skt)—Minor offences.
+ Mahavagga (skt)—Great Section.
+ Cullavagga (skt)—Lesser Section.
+ Parivara (skt)—Epitome of the Vinaya.
+ The perfect or complete (full) 250 commandments, which are obligatory on monks and nuns. 250 commandments are usually for monks, those for nuns are 348 (some says 500 commandments for the nuns).
Source (Vietnamese): http://daitangkinhvietnam.org/
Translated to English by TTLL (Thanh Tịnh Lưu Ly)