SEO stands for Search Engine Optimization. It is the process of getting traffic to the websites from organic, free or natural search results on search engines. All the major Search Engines have primary search results, where the content such as text or listings or videos or images are shown based on the what the search engines considers most relevant to users.
SEO is a process of improving the visibility of a website on organic or natural search engine results page (SERP). SEO has to be done in two different steps, one page and off page optimization