The document provides an overview of search engine optimization (SEO) and discusses what techniques should be avoided. It defines SEO as improving a website's placement in search engine results pages through legitimate means like on-page optimization and backlinks. The document outlines SEO's history and changing industry, noting keywords were once optimized through meta tags but search engines now prioritize off-page links. It describes nine illicit SEO techniques, or "black hat" methods, to avoid like keyword stuffing, cloaking, doorway pages, and hidden/tiny text, as these can get a site penalized for spamming.