This document provides an introduction to search engine optimization (SEO). It defines SEO as efforts to increase a website's ranking in search engine results pages. It discusses key search engines like Google and how Google uses algorithms like Panda, Penguin, and Hummingbird to evaluate websites and rank them based on factors like content quality, keyword optimization, and backlinks. The document stresses the importance of keeping SEO efforts focused on high-quality content marketing, social sharing to build quality backlinks, and ongoing analysis of SEO performance.