This document provides an overview of search engine optimization (SEO). It defines SEO as search engine optimization and discusses the objective of SEO is to rank a specific website for a targeted keyword. It also outlines different types of SEO such as paid SEO, organic SEO, on-page SEO, off-page SEO, and white hat, gray hat, and black hat SEO techniques. The document concludes by listing some important SEO tools, difficulty levels, and tips for keyword research.