Search engine optimization (SEO) is an important piece of the inbound puzzle. However, good rankings aren't the goal of inbound marketing – leads are (and, ultimately, sales).
SEO is a means to an end, not the end itself.
SEO is the art and science (yes, art) of using what is known of how search engines (especially Google) rank content and executing strategies that allow a company's Web pages to be ranked as high as possible.
A few things about SEO: