This document provides an overview of search engine optimization (SEO), including how search engines work, how to optimize a website for search engines, and potential pitfalls to avoid. It discusses how search engines index websites, use keyword relevance to determine search rankings, and evaluate over 200 factors. The document also outlines techniques to optimize on-page elements like titles, descriptions and internal links, as well as off-page elements like external links, and warns against black hat SEO tactics that try to artificially manipulate rankings.