‘Proofreading’ and ‘copy editing’ are terms often used interchangeably, perhaps it’s helpful to clarify that they’re different tasks.
The SfEP has produced a handy factsheet outlining the difference between the two.
Copy-editing is usually done to raw copy (i.e. your original manuscript – usually in Word) and is more detailed work than proofreading.
Proofreading is traditionally done after the text is typeset by a designer or typesetter, and pages (‘proofs’) have been produced. Its focus is much less interventionist: proofreaders generally expect the finer detail to have been covered during the copy-editing stage.
As a proofreader I always pick up any residual issues around language, sense and style, but at this stage I also read through the proofs to check headings, pagination, contents page and any references, and examine the layout to ensure all’s well. I can work on-screen or on hardcopy.
There is also an in-between provision called ‘proof-editing’: this is a hybrid kind of read which involves more intervention than what one would normally expect of a proofread.
If you’re an author or organisation needing a proofread, I’ll be happy to deliver.