Proofreading is meant for those writers who are on the cusp of publication. Everything is finished and previously edited with a fine tooth comb, and thus the document only requires a final check for misspelled or misused words, punctuation and capitalization errors, and so on. It makes sure that your grammar is up to par, that your speech is consistent (as in first person vs. third person vs. second person and so on), and that it is appropriate for your genre. Essentially, it is a final polish.
Copy editing is a more intense process. It involves everything that proofreading covers, as well as a check for the accuracy of the information you present: for instance, if your character gets into some trouble with the law, we check if your explaination of the law complies with reality to help you sell your character's predicament. If is a non-fiction manuscript, we double check your sources and quotations for accuracy according to peer sources and your particular citation format. It also involves a check of paragraph length, pagiation, and chapter length. This is the medium package and will serve most customers.
Content editing is an intense overhaul of your novel or manuscript and is a process that involves you at every turn. We reorder paragraphs, check for characterization, structure, flow of ideas, and so on, making sure that your novel is perfectly scultped to appeal to readers and publishers alike. This intense process involves several steps. First, your editor makes a close read of your novel/manuscript while taking notes on any inaccuracies or aspects that would likely turn off any readers, as well as any large areas requiring immediate rewrites. This allows you to make neccessary changes to your novel, without having to pay for another edit after your first is complete. As long as your page count remains within fifty pages of your original purchase, you are not invoiced any additional amount. Second, your editor begins working on document, making any necessary changes. Once complete, it is returned to you with comments for your to puruse and edits in track changes. You read over, make comments of your own, and then return it to your editor. Your editor reads it over while viewing, reacting, and responding to your comments, as well as checking to see that nothing was passed over.