It can be confusing! Line editing, copy editing, and proofreading are related but distinct services, and your manuscript may need one or more of these close readings.
Line editing focuses on style and language at the sentence and paragraph level, refining tone, clarity, and flow. Copy editing addresses mechanics such as grammar, punctuation, spelling, word choice, and repetition. Proofreading is the final quality check to catch remaining errors before submission or publication.