Search engines aim to provide happy searchers by ranking pages that will provide valuable information to users. They analyze over 250 factors on and off a website to determine a page's authority, relevance, and trust. Important on-site factors include keywords in the title, headings, text, and alt attributes as well as link structure and internal linking. Off-site factors like the number and quality of external links pointing to a page also impact rankings. The goal is to provide users with the most useful results.