introduction vs prepping

introduction

noun
  • The act or process of introducing. 

  • A written or oral explanation of what constitutes the basis of an issue. 

  • A means, such as a personal letter, of presenting one person to another. 

  • An initial section of a book or article, which introduces the subject material. 

prepping

noun
  • The action or process of preparing something, or preparing for something. 

  • The practice of making active preparations for a possible catastrophic disaster or emergency, typically by stockpiling food, ammunition, and other supplies. 

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