In 1900 Frank L Baum wrote a book called The Wonderful Wizard of Oz. In 1939 a film starring Judy Garland called The Wizard of Oz came out. This was based on the book, but differs in quite a few different ways (read the original book to find out where!). In 1995 the book Wicked was published. This was based on the original novel. Then the stage musical came out, which differs again to the novel of Wicked.
You'll find that the story of the tin man is different in each of the above!
Have a look here for more details
http://en.wikipedia.org/wiki/Wicked_(novel)