This document provides an overview of search engine optimization (SEO). It explains that SEO is the process of improving a website to rank highly in search engine results pages (SERPs) for targeted keywords. It discusses how search engines like Google work and rank websites, focusing on factors like relevant content, keywords, links, and social media. The document also outlines the main areas of focus for SEO, including choosing keywords, optimizing page structure and HTML, creating content, and using external applications and techniques.