The source material presents a podcast segment featuring Girish Kotte, who discusses the concept and evolution of prompt engineering. He defines prompt engineering as designing inputs for AI systems to achieve desired outputs, highlighting it as the art and science of communicating effectively with AI. The explanation traces its development through four key phases, beginning with basic queries, moving to context enhancement, progressing to role and format prompting, and finally reaching the current phase of advanced techniques like Chain-of-Thought and Few-Shot Learning. Kotte emphasizes that mastering prompt engineering is now essential for effectively leveraging AI capabilities and transforming interactions into powerful solutions.