“I am honored that Eleanor Expert has written the forward to my new book.”
Congratulations, Arthur D. Author, but Eleanor did not write a “forward.” She wrote a “foreword.”
This is a natural mistake, because the foreword appears “forward” of the book’s content, but the correct term is “foreword” – a word (idiomatically speaking) before the book begins.
Going forward, always use “foreword” when referring to the introduction to a book written by someone other than its author. If the author wrote it, it’s an “introduction.”