An introduction is basically written by the writer and is a part of the book. It usually gives the basics of what the book is about.
What should include in your introduction
1. Motivate your readers (instructor/friends) to read the collection of writings
2. Inspire your readers to envision what they might get out of the collection
3. Develop a relationship between you and your readers
4. Help readers understand how the collection of writings will help them
5. Tell readers how to get the most out of the writings