Pat McNees, writer, editor,
personal historian

What is the difference between a preface, a foreword, and an introduction? There is considerable confusion about the difference between the three, and judging from what the Chicago Manual of Style says, I mixed the two up myself in my history of the NIH Clinical Center, where an editor made my Introduction a Foreword, which I then changed to a Preface. It should have remained an Introduction.

Words into Type succinctly characterizes the differences between a preface and intro: "A preface or foreword deals with the genesis, purpose, limitations, and scope of the book and may include acknowledgments of indebtedness; an introduction deals with the subject of the book, supplementing and introducing the text and indicating a point of view to be adopted by the reader. The introduction usually forms a part of the text [and the text numbering system]; the preface does not."

The foreword, says the Chicago Manual of Style, is usually written by someone other than the author or editor, usually someone eminent (to lend credibility to the book), and although the title page may say "Foreword by X," if the foreword is only one or two pages (which is normal), the name of the foreword writer normally appears at the end of the foreword. (The title or affiliation of the author of the foreword may also appear there.) For details on positioning of these elements, and what kind of type to use, refer to one of those two manuals, if your publisher doesn't handle the formatting.

ORDER OF FRONT MATTER
The normal order of parts of the book is as follows:
Half title, or "bastard title" (title only, on otherwise blank page)
Book card (or card page, listing previous works by author, or books in same series)
Title page
Copyright notice (with other publishing notices)
Dedication
Blank
Table of contents (labeled "Contents")
(List of) illustrations
(List of) tables
Foreword (by another person)
Editor's preface
Author's preface
Acknowledgments (if not part of preface, or if not at back of book)
Introduction
[list of abbreviations, timeline]
Second half title (optional)
Text

ORDER OF BACK MATTER:
Appendix(es)
Notes
Glossary
Bibliography
(List of) Contributors (perhaps with brief biographical sketches)
Index(es)
Colophon (optional)

The epigraph (brief quotation or saying), according to Words into Type, may appear on the title page or on the back of the dedication or may replace the second half-title or be on the back of it, facing the text. To me it makes sense that it be near the text.

What are the purposes of a preface/​intro? Here are some purposes members mentioned at a meeting of the Washington Biography Group:
• To talk about how you came to write the book, especially if that will help draw the reader into the book. Perhaps best in the preface.
• To sell the book to the potential reader/​buyer (lure them, hook them, make them want to read more). In the case of Ruth Selig writing about the death of her twin, providing the personal details up front would be important, for example).
• To answer the question: why this book? why now? why this person? why by this author?
• To talk about how you got the information — what your main sources were(and how they differ from other books on the subject, if this is book #189 on the Kennedys, for example)
• To provide a framework for what's to follow — the hooks on which to hang the pegs of story details
• To provide, in brief, your main argument or point of view about the subject. The alternative is not to express your position clearly up front and to weave it into the fabric of the biography so that the reader has to read the book to find it. Critics may object to this. My impression is that you want to suggest your conclusions or viewpoint up front but express them more fully and strongly in the concluding chapter, if there are conclusions to be made.

Linda Lear wrote a prologue (a term from dramaturgy) to start her biography of Rachel Carson. A prologue starts the action and is PART of the action, though it could take place in the middle of the action — it often focuses on a pivotal moment. If you have a prologue, you must also have an epilogue.

Some people feel nobody reads the introduction; some people believe it's important because it’s the first thing people look at. Obviously it should be done well, if the latter is true even some of the time, but some people do skip it. Personally, I think it's important that everything in the book be interesting, because you never know where the reader will start, and you even want the ending to be good, so they leave feeling satisfied and you get good word of mouth. I tend to put acknowledgments at the back but try to make them interesting, to give them content.

SPELLING ALERT: Many people misspell foreword, as foreward or even forward! It is a "word" be"fore" the book itself. The foreword is usually written by someone other than the author.

On Wikipedia see preface, foreword, and introduction.