The grouped collection is characterized by its focus on three core complexes of reality that have been extensively addressed by the Enlightened One: the conditional origination of all things (Book II), the factors of existence (Book III), and the realm of the six senses (Book IV). The fifth and final book contains discourses on practical following and meditative practices. In total, there are 56 groups thematically presented in this collection, providing a rich resource for understanding and practicing the teachings of the Buddha.