Strictly speaking, proofreading means comparing a corrected version of a document with a previous version, one that has been marked to show the corrections that need to be made, and checking to confirm that corrections have been made.

However, proofreading is often taken to mean reading a document when it is believed to be ready for publication, and searching for 'fatal' errors. That is, the final checking of the document before printing.

This is what I mean by proofreading at Forbes Editorial Services. If a document has been thoroughly copy edited before being laid out for printing, my proofreading will be quicker (and cheaper) than copy editing.

On the other hand, if I am asked to proofread a document that hasn't been thoroughly copy edited, I will need to spend more time on it. I will tell you if this is the case.

My proofreading can be done in MS Word, or in Adobe Acrobat. The Edited examples page of this website shows examples in both formats.