Can you explain the concepts of Shreya and Preya as described in Chapter 17 of the Shri Sai Satcharitra?

Chapter 17 of the Shri Sai Satcharitra explains the fundamental difference between Shreya and Preya. Shreya represents the path of salvation and is described as the form of discrimination and pure Knowledge (Vidya). In contrast, Preya is the path of worldly joy, characterized as a form of ignorance (Avidya). The text states that just as light and darkness are of opposite natures, so too are Shreya and Preya. According to this chapter, a person whose mind is drawn to Preya falls away from their true self-interest, while the wise are never deluded by it. Choosing Shreya is presented as the true purpose of human life.