An important aspect of SEO is making your website easy for both users and search engine robots to understand. Although search engines have become increasingly sophisticated, they still can’t see and understand a web page the same way a human can. SEO helps the engines figure out what each page is about, and how it may be useful for users.
Getting the technical details of search engine-friendly web development correct is important, but once the basics are covered, you must also market your content. The engines by themselves have no formulas to gauge the quality of content on the web. Instead, search technology relies on the metrics of relevance and importance, and they measure those metrics by tracking what people do: what they discover, react, comment.