Search engine optimization (SEO) involves optimizing websites to increase their visibility in organic search engine results. Search engines use algorithms to analyze websites and determine relevance and importance. Proper on-page optimization of keywords, content, and links can help a site rank higher in search results. Eye tracking studies show users focus on top-ranked results, so SEO is important for driving traffic and achieving business goals like increased sales. A case study demonstrates how SEO helped a diabetes product website rank for competitive keywords and increase its traffic by over 300%. Key factors for online success include setting goals, researching competitors and keywords, optimizing content and links, and monitoring results.