SEO abbreviate as search engine optimization and used to ranking up a Website on search engines like Google.
SEO works on basis of keywords.
Keywords are sets of words that make searching easy, rank up a website on search engine. In on page SEO word tag's are used to rank up each service/Product page on search engine. SEO make searching of service/Product easy to customers who search it on engine.
SMO abbreviate as social media optimization. In age of social media it is very easy to reach customers as huge crowd of netgens are on social site.
Netgens are the person who can makes a post viral on internet. By posting a properly managed post about a Products/services on social media facebook, twitter, instagram, whatsapp, linkden, pinterest make it popular.