The discussion centers on the effects of impurities on the boiling point of liquids, specifically addressing non-volatile and volatile impurities. Non-volatile impurities raise the boiling point because they reduce the vapor pressure of the solvent, requiring a higher temperature to reach the external pressure, as explained by Raoult's law. In contrast, the presence of volatile impurities can increase vapor pressure since they can vaporize themselves, potentially lowering the boiling point. The conversation emphasizes the relationship between vapor pressure, temperature, and boiling point, while also acknowledging the importance of understanding these concepts for better comprehension of physical chemistry.