SEO, or Search Engine Optimization, is optimizing websites to improve their ranking and visibility on search engine results pages (SERPs). The higher a website appears on SERPs, the more likely it is to receive user clicks, which can translate to increased traffic, leads, and sales. SEO encompasses a range of strategies, including keyword research, on-page optimization, off-page optimization, and technical optimization. By following best practices and keeping up with changes in search engine algorithms, website owners can improve their chances of ranking well on SERPs and reaching their target audience.