The discussion centers on the various editions of Jackson's "Classical Electrodynamics," highlighting key differences among them. The main distinctions include the absence of the Magnetohydrodynamics chapter in the third edition, which is present in the first and second editions. The third edition predominantly uses SI units, while it reverts to Gaussian units in later chapters, a feature that some users appreciate for its relevance in physics. The third edition is noted for being more contemporary, particularly in its computational methods, reflecting advancements in electromagnetics since the earlier editions were published. Preferences vary, with some users favoring the second edition for its use of Gaussian units, which they consider superior for theoretical physics. Overall, the choice of edition may depend on individual comfort with units and specific content preferences.