Introduction

Noun

1. The act or process of introducing.

   "the introduction of a new product into the market"

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

   "David was feeling groggy at his introduction to Sophie, and didn't remember her name."

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

   "This book features a preface by a well-known botanist, and an introduction by the author's mentor at university."

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

   "ECON 101: introduction to economics"