SEO stands for Search Engine Optimization. It refers to the practice of optimizing a website or web page to improve its visibility and ranking in search engine results pages (SERPs). The ultimate goal of SEO is to increase organic (non-paid) traffic to a website by making it more relevant and authoritative in the eyes of search engines. Search engines like Google, Bing, and Yahoo use complex algorithms to determine the relevance and quality of websites when users enter search queries. SEO involves various techniques and strategies to align a website's content, structure, and technical aspects with these algorithms to improve its chances of ranking higher in search results.