What are the three types of poetic books mentioned in the preface, and which category does Shri Sai Satcharita belong to?

The preface to Shri Sai Satcharita, as detailed in chapter 0, outlines three distinct types of poetic books: natural, graceful (Prasadik), and artificial. It explains that a book written purely from scholarship and intelligence is considered artificial and will not have an eternal quality or inspire genuine faith. The Shri Sai Satcharita itself is identified as a 'grace-filled' or 'Prasad-janya' book. This classification signifies that it is born not just of human intellect, but of divine grace and inspiration from the Guru. This inherent quality is presented as the reason the book is so impactful and beloved by seekers.