epilogue vs preface

epilogue

noun
  • A brief oration or script at the end of a literary piece; an afterword 

  • A short speech, spoken directly at the audience at the end of a play 

  • A component of a computer program that prepares the computer to return from a routine. 

  • The performer who gives this speech 

verb
  • To conclude with an epilogue. 

preface

noun
  • The beginning or introductory portion that comes before the main text of a document or book. 

  • An introduction, or series of preliminary remarks. 

  • A title or epithet. 

  • The prelude or introduction to the canon of the Mass. 

verb
  • To give a preface to. 

  • To introduce or make a comment before (the main point). 

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