Defamation is the tort everyone thinks they understand and almost nobody does. This article walks the whole structure — the six elements a plaintiff must actually prove, why "of and concerning" and publication do more work than people expect, and how the constitutional overlay built from New York Times Co. v. Sullivan through Gertz and Hepps reassigns the burden of proof depending on who the plaintiff is and what the statement is about. It explains the three fault standards, the difference between falsity and provable falsity after Milkovich, why calling something "just my opinion" changes nothing, and how defamation by implication lets literally accurate reporting still be actionable. It then takes up the problems the internet created: the single publication rule and what counts as republication, why Section 230 is not a defamation defense but an immunity for a different party, the anti-SLAPP patchwork and its unresolved federal-court split, and what happens when a language model generates a false statement about a real person. The piece closes with damages, insurance, and the practical arithmetic that decides whether a defamation case is worth bringing.