What is Ghost Writing?

All this time, I was unaware of the term, however today I got an opportunity to do some research and found that people who write for somebody else, just because the person does not have time and space are termed as Ghost writers, e.g. It may be a celebrity who wants to write a autobiography however does not find time for that, so the celebrity employs the ghost writer who does the needful on behalf of the celebrity and the book is published in the Celebrity’s name. Ghost writing is quite challenging because the writer needs to do extensive research on the person whom he is writing about, also keeping in mind the opinions and ideas as being voiced by the Celebrity himself, for doing this task he needs to step into the celebrity shoes and should portray his writing such that the audience does not get an faint idea that someone else has written the book.