When it comes to writing, there really is no difference. But in your association with your client, there is a world of difference.
Whether you’re the ghostwriter or the co-author of a book, your job is to work with your client to get your messages across. It is a collaboration. You can take their opinion and write the entire book yourself, if you have this degree of freedom. Or it may end in a back-and-forth process: she gives you a draft, which you edit, and send back. She makes changes and additions and returns it. Edit your changes and add new material. And so it goes, each of you taking a turn until the final draft is finished and you are both satisfied with the final result. As a co-author or ghostwriter, you follow this process. Or develop whatever writing and review process works best for you and your client.
Where the difference comes in is how your customer sees you. If you are the Invisible and unknown writer behind the scenes., you are technically a ghostwriter. If you are a publicly known contributor to the author, then you are considered a co-author.
The major distinction between the two roles involves a not-so-trivial matter called confidentiality. Some authors who hire professional writers do not want others to know that they are getting help. It is a matter of image or perception. For various reasons, there is a genuine need to be perceived as the sole creator of the book. These authors will look for ghostwriters who know how to be discreet. For other authors, confidentiality is not an issue, so having a visible co-author is perfectly acceptable.
A ghostwriter, then, must be an expert at working behind the scenes. Confidentiality must be taken seriously, which means you can’t tell people who you are writing for; You are not allowed to reveal your client’s name or project details. When the book is published, you cannot claim any ownership or association. On your resume, you can state generalities such as, “Wrote a book on new gardening techniques.” But it cannot reveal the title of the book or the name of the author.
With a co-author, secrecy is not required. Since the co-author’s name appears on the title page next to the author’s name, there is no need to hide the collaboration. On her resume, the co-author is free to include the title and author of the book.
Before embarking on a book collaboration with a new client, find out what the confidentiality expectations are. Can you talk openly about the project or does your client expect you to keep things a secret forever? Knowing these conditions beforehand will prevent you from putting your foot in your mouth and ruining your reputation. As a professional writer, it is your job to work out all terms, including confidentiality and whether you are considered a ghostwriter or co-author, before you start writing.