When your document has been written, edited and the layout has been designed, it’s almost ready for publication. It’ll just need one final check to make sure everything is as it should be. This is where the proofreader comes in – to catch any last-minute errors that have made it onto the page. Generally speaking, the proofreader should not be the same person as the copy-editor; a fresh pair of eyes is very important at this final stage.
Copy-editing typically happens after the document has been written but before the designer or typesetter lays it out on the page. The editor acts as a bridge between the writer and the designer, correcting errors in the text and, if appropriate, indicating to the designer where the illustrations, tables and so on should go in the finished work.