"Editing involves a proactive editor making changes and suggestions that will improve the overall quality of your writing, particularly in relation to language use and expression. After editing, your language will be sharp and consistent, your expression clear and the overall readability of your writing enhanced. Editing should ensure that your writing gives the impression that the English language comes naturally to you, even if it does not."
"Proofreading, on the other hand, has less ambition than editing and is therefore a cheaper service, but it still performs a vital role. Proofreading is the process of correcting surface errors in writing, such as grammatical, spelling, punctuation and other language mistakes."