SEO is important because search engines have become the primary way people find information online. To succeed at SEO, a website needs to make its content accessible and relevant to search engines through techniques like optimizing titles, URLs, meta descriptions and on-page content for target keywords. It also needs to build links, social shares and citations from authoritative sources to gain the search engine's trust. Regular tracking and testing of rankings, usability and conversions is required to continuously improve search performance.