SEO means Search Engine Optimization and is the process used to optimize a website's technical configuration, content relevance and link popularity so its pages can become easily findable, more relevant and popular towards user search queries, and as a consequence, search engines rank them better.
Search engines recommend SEO efforts that benefit both the user search experience and page’s ranking, by featuring content that fulfills user search needs. This includes the use of relevant keywords in titles, meta descriptions, and headlines (H1), featuring descriptive URLs with keywords rather than strings of numbers, and schema markup to specify the page's content meaning, among other SEO best practices.
Search engine optimization (SEO) is the practice of orienting your website to rank higher on a search engine results page (SERP) so that you receive more traffic. The aim is typically to rank on the first page of Google results for search terms that mean the most to your target audience. So, SEO is as much about understanding the wants and needs of your audience as it is about the technical nature of how to configure your website.