Search engine optimization (SEO) concentrates on promotion of a website's website within organic (free) results of a search, in order to increase its visibility in search results for words and phrases that the users utilize.
The Pay-per-Click (PPC) marketing provides advertisements to these same users that are based on demographics, keywords or any other criteria - however, it is an auction-based method which charges the advertiser per click for their ad.
PPC advertising is accessible on a wide range of internet platforms which include search engines like Google and Bing and social media platforms such as Facebook as well as Linkedin.
SMM (social media marketing) is the method of increasing brand recognition and engagement across various social media platforms. You develop your own brand identity and advertise your products or services on every platform.