SEO is the concept to legitimatize and optimize websites for listings in search engines on Google. To simplify, It is the process of getting traffic from “free” and “organic” search results. Click here to join the Google party.
Google must consider your website relevant. This is mainly to be gauged by analysing the numbers & links from other parts of the interweb. You stand a better chance of rank higher as long as other pages are linked back.
SEO has various strategies to increase traffic ranging from intentional link and optimising your site faster for related keywords in the content.
Without the proper SEO, your website and the content wouldn’t be relevant or ranking high enough to get the clients you need.