SEO Defined. (Search Engine Optimization). Search engine optimization (SEO) is simply the practice of making your website or blog more accessible to both search engines and search engine users. It is the process of overseeing the development or re-development of a website, so that it will naturally attract traffic by securing top ranking on the major search engines and/or directories for selected search terms and phrases. In other words, you`re making it easier for them to find you.