The discussion focuses on recommendations for books specifically about photons, with an emphasis on optics and classical electrodynamics. Participants clarify whether the inquiry pertains to advanced studies or more popular-level texts. Notable suggestions include Richard Feynman's "QED: The Strange Story of Light and Matter," which is accessible yet informative. The conversation highlights the need for resources that cover topics such as interference, diffraction, and advanced diffraction, indicating a preference for comprehensive study materials in these areas.