Line editing vs. copyediting: the real difference
Line editing and copyediting are often confused because both work at the sentence level. The difference is intent. Line editing asks: is this sentence doing its job well? Is it clear, rhythmic, precise, and consistent with the voice of this book? Copyediting asks: is this sentence grammatically correct and consistent with the style guide? Line editing is an art judgment. Copyediting is a rules check. Both matter, and neither replaces the other.