A book is composed of many parts, including a LEAF, COVER, CHAPTER, PAGE, INDEX, endpaper, FOLIO, PREFACE, SPINE, PAGES, END, spne, TITLE, and JACKET. A LEAF is a single sheet of paper in a book, while the COVER is the protective outer layer of a book. Chapters are divisions of a book that are usually numbered or titled, and a PAGE is one side of a LEAF. An INDEX is an alphabetical list of topics found in a book, and endpapers are the sheets of paper at the beginning and END of a book. A FOLIO is a large sheet of paper folded once to form two leaves, and a PREFACE is an introduction to a book. The SPINE is the binding along the edge of a book, and PAGES are the sides of a LEAF. The END is the last part of a book, and a spne is a misspelling of SPINE. The TITLE is the name of a book, and a JACKET is a protective COVER for a book.