SEO (search engine optimization) involves setting up website content and metadata to improve a site's visibility in organic search results. The document provides examples of metadata like meta titles, descriptions, and keywords that universities and e-commerce sites can use to better optimize their SEO, such as describing the Independent University of Bangladesh as one of the top universities in Bangladesh. It also mentions that page speed and web performance are factors search engines consider in rankings, so sites should focus on efficient use of bandwidth and server resources.