How exactly does SEO work?

Suppose you write an article and share it on social media. The article is then, say, viewed 200 times. If you combine this with SEO, then you get those 200 initial visit and after a few months (it takes a while before you start to rank), every month 40 extra visitors from the search engine. Multiply this by a few years (in 36 months, for example) and dozens of optimized articles. To know more just read this article.