Copyediting includes checking written material for grammar, spelling, style, clarity and punctuation issues. A copyeditor may rewrite sections of text to fix any problems with transitions, wordiness, jargon or repetitiveness, and to ensure the continuity of the writing style; this is particularly relevant where the nationalities of the authors differ.
Importantly, the copyeditor will edit your document to reflect your specific three Ws:
Who – Who is your target audience?
What – What is the core message of the document?
Why – What do you wish to achieve by publishing the document?