SEO, or Search Engine Optimization, is the practice of optimizing websites to increase their visibility and ranking in search engine results pages (SERPs). The primary goal of SEO is to attract organic (non-paid) traffic to a website by improving its relevance, authority, and user experience in the eyes of search engines like Google, Bing, and Yahoo. SEO involves various techniques and strategies, including keyword research, on-page optimization (such as optimizing content, meta tags, and URLs), off-page optimization (such as link building and social media engagement), technical optimization (such as improving site speed and mobile-friendliness), and user experience optimization. By implementing SEO best practices, website owners can improve their chances of ranking higher in search engine results for relevant queries, thus driving more targeted traffic to their sites and potentially increasing conversions and revenue.