SEO is search engine optimization, a set of strategies to improve a website's visibility on Google and other search engines. It includes the optimization of keywords, loading speed, user experience, internal and external links, and quality content. Good SEO allows for attracting organic traffic without paying for ads. It is divided into On-Page SEO (optimization within the site) and Off-Page SEO (external factors such as backlinks). Tools like Google Search Console, Ahrefs, and SEMrush help to analyze and improve a website's positioning.