This document provides an overview of domain names and search engine optimization (SEO). It defines what a domain name is and how domain names are organized from general to specific descriptors separated by periods. It also distinguishes between a domain name and a URL. The document then discusses top-level domains (TLDs), country code TLDs, and how domain names are spelled. It provides examples of common TLDs and an overview of web hosting types. Finally, it introduces the basics of SEO, SEM, and how they can help drive more visitors to a website.