Search Engine: An internet-based tool that searches an index of documents for a particular term, phrase or text specified by the user. Commonly used to refer to larger web-based search engines that search through billions of pages on the internet.
SEO is the process of improving the volume and quality of traffic to a website from search engines via “organic” or “algorithmic” search results for target keywords. SEO can also target different kinds of searches, including : -
Industry-specific vertical search engines
SEO is the art/science of getting a webpage ranked highly on the major search engines.
Natural Search, Organic Ranking, Organic Search or SEO all are same.
SEO considers how search algorithms work and what people search for.
Another technique known as Black Hat SEO or Spam Indexing