You are reading the System Reference Document for Sufficiently Advanced - a condensed version of the rules that can be found in the Second Edition corebook. This section describes the major technology in the game. The other sections are the Game Play and Character Creation sections, which teach you the rules of the game and how to create characters for it. You can also find many terms defined in the Glossary.
Technology is at the heart of Sufficiently Advanced. Every Civilization, many Societies, the very numbers that describe your character, all revolve around the use of technology and the choices people make with it. This section introduces the most important technology that appears in the game and helps you understand its impact.