The Web has millions of web pages. Amidst all the information out there, useful and not-so-useful, getting your web page noticed might be a very difficult task.
A web page might provide extremely useful and relevant information, but just because of the sheer numbers out there, that page might get very few hits and very few visitors. This is more so, if this page appears on the ‘15th’ page of search results! It is much more likely that a person visits a page on the 5th page of a search result than say, the 15th page (the earlier a site appears in the search results list, the more visitors it will receive from the search engine).
From this idea, it is obvious that one of the ways to increase traffic to a page is to get a high ranking for this page on search engine return pages (SERPs) i.e. making your page appear earlier on when a user queries a search than later.
From this, we can quite simply say that search engine optimization (SEO) is the process of improving the volume and quality of the traffic to a web page via a search engine.
SEO does not specifically target only a general text search; it can also target different kinds of search like an image search, a local search, or an industry-specific vertical search.
Now, imagine you create a website on ‘Cricket’. If your site is very new, it is probably not even listed on any SERPs. So an obvious first step would be submitting your web page to search engines like Google and Yahoo. Even with the best information about Cricket on the Web, your site might not turn up on the top page of the results of these search engines. When people search for the term “Cricket”, they would probably end up going to inferior sites as compared to yours, only because your page is not in the top few result pages.