appendix vs foreword

appendix

noun
  • A text added to the end of a book or an article, containing additional information. 

  • Any process, prolongation, or projection. 

  • The vermiform appendix. 

foreword

noun
  • An introductory section preceding the main text of a book or other document; a preface or introduction. 

How often have the words appendix and foreword occurred in a corpus of books? (source: Google Ngram Viewer )