Copy editing is what most people think of when they think of editing. It focuses on the mechanics and grammar of the material, ensuring that everything is correct, accurate and consistent. At this point in the editing process, the majority of the writing should be completed. This is the polishing stage and there shouldn't be a need for major rewrites or reformatting of ideas.
This includes but is not limited to:
Correcting errors in spelling, grammar and usage
Checking that facts are correct
Ensuring consistency in spelling, numbers and abbreviations
Flagging necessary citations, copyrights and permissions
Ensuring the material is complete
Copy editing is done in Word using track changes. At the end of the process two versions will be returned: a clean copy with all of the changes accepted and a marked up copy with all of the changes visible.
The copy edit may also contain elements of a stylistic edit which clarifies meaning, ensures coherence and flow and refines the language.