Pārājika Pāḷi, which is the first book of the Vinaya Piṭaka, gives an elaborate explanation of the important rules of discipline concerning pārājika and  saṅghādisesa, as well as aniyata and nissaggiya which are minor offences.

Pārājika discipline consists of four sets of rules laid down to prevent four grave offences. Any transgressor of these rules is prohibited from becoming a bhikkhu. In the language of Vinaya the pārājika āpatti falls upon him. He automatically loses the status of a bhikkhu, he is no longer recognized as a member of the community of bhikkhus, and he is not permitted to become a bhikkhu again. He either has to go back to the household life as a layman or return to the status of a sāmaṇera (novice).

Saṅghādisesa discipline consists of a set of thirteen rules which require formal participation of the Sangha from beginning to end in the process of making him free from the guilt of the offence.    

Aniyata means indefinite, uncertain. There are two aniyata offences where it is unclear whether they are a pārājika offence, a saṅghādisesa offence or a pācittiya offence.

Nissaggiya: There are thirty rules under this category of offences and penalties which are laid down to curb greed in bhikkhus for possession of material items such as robes, bowls etc. (To give an example, an offence is committed under these rules when objects not permitted are acquired, or when objects are acquired in more than the permitted quantity. The penalty consists firstly of giving up the objects in question. This is followed by confession of the breach of the rule together with an undertaking not to repeat the same offence, to the Sangha as a whole, or to a group of bhikkhus, or to an individual bhikkhu to whom the wrongfully acquired objects have been surrendered.)

The Pācittiya Pāḷi, which is the second book of the Vinaya Piṭaka, deals with the remaining sets of rules for the bhikkhus, namely, the pācittiya, the pāṭidesanīya, the sekhiya, the adhikaraṇasamatha and the corresponding disciplinary rules for the bhikkhunis.

Although it is called in Pāḷi just pācittiya, it has the distinctive name of suddha pācittiya (ordinary pācittiya), to distinguish it from nissaggiya pācittiya, described above.

Pācittiya: There are ninety-two rules under this class of offences classified into nine sections. A pācittiya offence is remedied merely by admission of the offence to a bhikkhu.

Pāṭidesanīya: There are four offences under this classification and they all deal with the bhikkhu’s conduct in accepting and eating alms-food offered to him. The bhikkhu breaking any of these rules must use a special formula stating the nature of his fault when admitting his offence.

Sekhiya: These seventy-five rules laid down originally for the proper behavior of bhikkhus also apply to novices who seek admission to the order. Most of these rules were laid down at Sāvatthi as a result of undisciplined behavior by a group of six bhikkhus.

The rules can be divided into four groups. The first group of twenty-six rules is concerned with good conduct and behavior when going into towns and villages. The second group of thirty rules deals with polite manners when accepting alms-food and when eating meals. The third group of sixteen rules contains rules which prohibit teaching of the Dhamma to disrespectful people. The fourth group of three rules relates to unbecoming ways of answering the calls of nature and of spitting.

Adhikaraṇasamatha: Pācittiya Pāḷi concludes the disciplinary rules for bhikkhus with a chapter on (four types of disputes and) seven ways of settling disputes.

Rules of Discipline for the Bhikkhunis: The concluding chapters in the Pācittiya Pāḷi are devoted to the rules of discipline for the bhikkhunis. The list of rules for the bhikkhunis is longer than that for the bhikkhus. The bhikkhunis rules were drawn up on exactly the same lines as those for the bhikkhus with the exception of the two aniyata rules which are not laid down for the bhikkhuni order.

The next two books, namely, Mahāvagga Pāḷi which is the third book and Cūḷavagga Pāḷi which is the fourth book of the Vinaya Piṭaka, deal with all those matters relating to the Sangha which have not been dealt with in the first two books.

Mahāvagga Pāḷi, made up of ten sections known as khandhakas, opens with an historical account of how the Buddha attained supreme enlightenment at the foot of the Bodhi tree, how he discovered the famous Law of Dependent Origination and how he gave his first sermon to the group of five bhikkhus on the discovery of the Four Noble Truths (i.e. the great “Discourse on the Turning of the Wheel of Dhamma”-Dhammacakkappavattana Sutta). This was followed by another great discourse, the Anattalakkhaṇa Sutta. These two suttas can be described as a compendium of the teaching of the Buddha.

The first section continues to describe how young men of good families like Yasa sought refuge in him as a Buddha and embraced the Dhamma; how the Buddha embarked upon the unique mission of spreading the Dhamma “for the welfare and happiness of the many” when he had collected around him sixty disciples who were well established in the Dhamma and had become arahats; how he began to establish the order of the Sangha to serve as a living example of the truth he preached; and how his famous disciples like Sāriputta, Moggallāna, Mahā Kassapa, Ānanda, Upāli, Aṅgulimāla became members of the order.

The same section then deals with the rules for formal admission to the order (upasampadā) giving precise conditions to be fulfilled before any person can gain admission to the order and the procedure to be followed for each admission.

Mahāvagga further deals with procedures for an uposatha meeting, the assembly of the Sangha on every full moon day and on the fourteenth or fifteenth waning day of the lunar month when pāṭimokkha, a summary of the Vinaya rules, is recited. Also there are rules to be observed for rains retreat (vassa) during the rainy season as well as those for the formal ceremony of pavāraṇā concluding the rains retreat, in which a bhikkhu invites criticism from his brethren in respect of what has been seen, heard or suspected about his conduct.

There are also rules concerning sick bhikkhus, the use of leather for footwear and furniture, materials for robes, and those concerning medicine and food. A separate section deals with the kathina ceremonies where annual making and offering of robes take place.

Book four of the Vinaya Piṭaka, deals with further rules and procedures for institutional acts or functions known as saṅghakamma. The twelve sections in this book deal with rules for offences such as saṅghādisesa that come before the Sangha; rules for observance of penances such as parivāsa and mānatta and rules for reinstatement of a bhikkhu.

There are also miscellaneous rules concerning bathing, dress, dwellings and furniture and those dealing with treatment of visiting bhikkhus, and duties of tutors and novices.

Some of the important enactments are concerned with tajjanīya kamma, a formal act of censure by the Sangha taken against those bhikkhus who cause strife, quarrels and disputes, who associate familiarly with lay people and who speak against the Buddha, the Dhamma and the Sangha; ukkhepanīya kamma, the formal act of suspension to be taken against those who, having committed an offence, do not want to admit it; and pakāsanīya kamma, taken against Devadatta announcing publicly that “Whatever Devadatta does by deed or word, should be seen as Devadatta’s own and has nothing to do with the Buddha, the Dhamma and the Sangha.”

The account of this action is followed by the story of Devadatta’s three attempts on the life of the Buddha and the schism caused by Devadatta among the Sangha.

In section ten there is the story of how Mahāpajāpatī, the Buddha’s foster mother, requested admission into the order, how the Buddha refused permission at first, and how he finally agreed to the request because of Ānanda’s appeal on her behalf.

The last two sections describe two important events of historical interest: the holding of the first Synod at Rājagaha and of the second Synod at Vesāli.

Parivāra Pāḷi, which is the fifth and last book of the Vinaya Piṭaka, serves as a kind of manual. It is compiled in the form of a catechism, enabling the reader to make an analytical survey of the Vinaya Piṭaka. All the rules, official acts, and other matters of the Vinaya are classified under separate categories according to the subjects dealt with.

Parivāra explains how rules of the order are drawn up to regulate the conduct of the bhikkhus as well as the administrative affairs of the order. Precise procedures are laid down for the settling of disputes and the handling of matters of jurisprudence, for the formation of Sangha courts and the appointment of well-qualified Sangha judges. It lays down how the Sangha Vinicchaya Committee, the Sangha court, is to be constituted with a body of learned vinayadharas (experts in Vinaya rules) to hear and decide all kinds of monastic disputes.

The Parīvara Pāḷi provides general principles and guidance in the spirit of which all the Sangha Vinicchaya proceedings are to be conducted for the settlement of monastic disputes.