I’ve had this question come up twice this week, so I thought I would address it as a blog post today!
For new authors, it is sometimes confusing to tell which of these four you should use in your book. The simple answer is that you can use whichever one you think works best for you and the content of your book. You can even use all three in the same book, if that’s what you prefer, just keep in mind that many readers tend to skip most book intros, prefaces, and forewords. Since Author’s Notes are usually a little more personal, readers might be drawn to reading those more than they would an introduction. Before you choose which one(s) to use, however, it’s helpful to know the purpose each one serves and how to use them appropriately.
Author’s Note: Author’s notes are often used when an author wishes to explain why they chose to write about the topic their writing about. It helps prepare readers for the content in the book and gives them a glimpse into what the author was thinking before, during, and after writing the book. If your book is addressing a controversial topic, the author’s note is a great place to prepare your readers for what’s to come and to explain to them why you feel strongly about the topic and how it affects you personally.
Introduction: The purpose of the introduction is to introduce your readers to the topic addressed in your book. It can be written either by the author or by someone else.
Preface: The preface has similarities to the author’s note in that it explains to readers how the author came to write the book. It provides the backstory and its relationship to the book’s topic. The preface is typically written by the author and usually tells a personal story.
Foreword: The foreword is almost always written by someone else besides the author. Many times, this someone else is a master in the topic being discussed in the book or is a celebrity of some sort. The point of having a foreword is to lend credibility to the author and his/her book. Many times, a relationship already exists between the author of the foreword and the author of the book, but in many other instances, there is no relationship besides a shared interest in the topic of the book. Forewords generally don’t serve any other purpose besides being powerful advertisements for the release of the book.
If you choose to use 1, 2, 3, or all 4 in your book, it is also useful that you know how to order them. The author’s note, preface, introduction, and foreword all come before the content or first chapter of your book (and are known as a book’s front matter). Here is how to order them after your copyright page, dedication, and table of contents (if you have one):
I hope this helps you to decide what to include in your book's front matter. A professional editor can help you narrow things down if you're unsure.