The source code consists of all the text and LaTeX commands that make up an entire document.
The source code is typed in using a text
editor[TeX-friendly editors and shells], and saved with
the file extension .tex. The source code may be contained
in just one file, or it might be split across several files.
2.1 Source Code
This book is also available as A4 PDF or 12.8cm x 9.6cm PDF or paperback (ISBN 978-1-909440-00-5).