Your raw text, or copy, of research needs a language that is free from any grammar and spell errors so that the readers don’t get trapped in the flaws, while trying to understand your idea. Enhancing your copy and preventing embarrassing errors is what a copy-editor does to your set of words. To the benefit of publishers, a copy editor alerts about the possible legal issues and ensures that the typesetter can do a correct job.
Professional Copy-editors lay their eyes on the following:
• Language Suitability for the intended audience
• Logical transition between paragraphs and separate sections
• Consistency of text such that the illustrations and tables go in-line with the text and objectives
• Accuracy of spellings and adoption of the correct writing style
• Technical matters of publishing
There still more that copy-editors do, apart from the basic function of correcting spelling, grammar and punctuation.