Based on the preface, compare the two types of literary service a Sadguru accepts from devotees.

Chapter 0 outlines two distinct types of service a Sadguru takes through books. The first is when the Guru, like Shri Dnyaneshwar, creates a great work themselves. The second is when the Guru has their biography written through a devotee, such as the Shri Sai Satcharita penned by Annasaheb Dabholkar. This second form of service is profoundly communal. It allows the writer to perform Guru service, while also enabling the entire congregation of devotees to render service through their collective study and 'Parayans,' helping them achieve the purpose of their lives and fostering a sense of shared spiritual practice.