Can you explain the concepts of 'Kamya' and 'Nishkam' service as they apply to studying a Guru's biography?

As detailed in Chapter 0, the study of a Guru's biography can be approached in two distinct ways: with desire (Kamya) and with a selfless mind (Nishkam). Kamya service is performed for worldly purposes, such as achieving prosperity or seeking relief from worries, calamities, and diseases. In contrast, Nishkam service is selfless and undertaken with the sole purpose of attaining liberation from the world and the cycle of birth and death. The text unequivocally states that Nishkam Guru service, being selfless, is always considered the superior path, whether one is studying a biography or other spiritual knowledge texts.