Vinaya Pitaka
The first category, the "Vinaya Pitaka", is mostly concerned with the rules of the "sangha", both monks and nuns. The rules are preceded by stories telling how the Buddha came to lay them down, and followed by explanations and analysis. According to the stories, the rules were devised on an ad hoc basis as the Buddha encountered various behavioral problems or disputes among his followers. This pitaka can be divided into three parts: