Also known as line-by-line editing, copy editing makes sure you're saying what you think you're saying in the way you want to say it. (Handy stuff!)
Copy editing comes after structural editing. (It’s no use getting the words and sentences all lined up if you don’t have the overall narrative sorted.) A manuscript appraisal will identify the main areas to improve your work line-by-line.
Copy editors ask questions of the author to ensure that each word, sentence and paragraph is expressed as clearly as possible. Among other things, experienced copy editors ask:
Can this sentence be expressed more concisely?
Will the intended audience engage with these words?
Does the reader have all that they need?
Could the voice be more consistent here or here or here?
What do you mean when you say X or Y or Z?