On-page and off-page optimization are the two main categories of SEO that can improve a website's search engine ranking. On-page optimization focuses on improving elements on the actual website like content, headers, images and file indexing to enhance user experience. Off-page optimization involves activities off the website like developing promotional content, listing the site on directories, and generating niche related content to build links and visibility. Proper SEO through both on-page and off-page methods is necessary to help a website rank higher in search engine results pages.