You can get the idea of how popular this way is when somebody says "don't you get it?...just Google it". Thus to attain a high ranking on search engine return pages (SERP's) becomes the obvious means to improve targeted traffic.
Search engine optimization (SEO) is the process of improving the visibility of a website or a web page in search engines via the "natural" or un-paid ("organic" or "algorithmic") search results. Having a website without being exposed to your potential customers is like having a store full of products in the desert. There are millions of web pages circulating in the internet. The key is how can my website be indexed and retrieved by the search engine in the first page.