ordination as a Buddhist Bhikshu (monk) or Bhikshuni (nun) can be seen both as the culmination of a period of intense preparatory cultivation and as the beginning of a new and fuller life in the Dharma.
The preparatory period begins with taking Refuge with the Triple Jewel (see entry), that is, formally becoming a Buddhist and bowing to a Teacher. It is followed by stages of learning to live in accord with progressively higher standards of purity and morality]] as represented by adherence to moral precepts (see entry). The taking of the Five Precepts (see entry) is followed by the eight precepts and then often the Bodhisattva precepts (see BNS). The taking of the Novice (Shramanera) precepts (see SV) ushers in a period of a minimum of Three years formal training for becoming a fully-ordained Bhikshu or Bhikshuni.
ordination itself takes place in a Ceremony open only to the Sangha that is presided over by ten elder Bhikshus of high virtue. During the Ceremony the 250 Bhikshu Precepts (or 348 Bhikshuni precepts) are transmitted.