SEO and SMO both are important for web ranking. SEO is essential for improving website visibility, increasing your traffic and sales online. SEO is short for Search Engine Optimization, which is the on-going process of improving the visibility and ranking of a website or web page in the organic search engine results presented in Google and the other major search engines.
Social media optimization is exposing your website on social media channels like Facebook twitter; it helps you in building good social media reputation with more traffic, which is considered by Google while ranking your website in search results.