Search Engine Ranking and Domain Names

I see many questions in forums and social networks about the effect a domain name has on the search engine ranking of a website. The most common questions I have seen relate to: Using hyphens between words of a domain name Including primary keywords in a domain name The TLD of a domain name(i.e. – .com, .net, .us, etc.) Based on feedback from the experts, and reference materials from Google, we will summarize the answers to these issues.