Today the amount of information,that we can get from the Web, is increasing more and more. Although it is very useful that everyone can retrieve all the information he needs in his work using just an Internet connection, on the other hand this requires a quick and efficient way to find what actually he is looking for.
Search engines are the world famous solution to the problem; they are an interface to the information: transcending user categories, geographic regions, and information seeking goals, they allow us to find in few minutes the main websites related to the argument we are interested in. Unfortunately the task to present us only the pages which are relevant to the keywords that you type is not trivial, it requires to crawl all the Web, index all the pages according to their content and then to rank these page to present them to the user in the correspondent order. In particular the critical part is when a search engine has to assign how much a page is relevantly related to a particular keyword; understanding the rules and algorithms used in this process is fundamental to increase the chances of gaining position in the ranking order of your website. The higher is this position and the greater is the probability that someone will arrive to your website through a search engines.
Search Engine Optimization (SEO) is the activity of optimizing a website in order to make it more search engine-friendly. Already in the 2003 these and directories average over 300 million searches per day and it was showed that the users usually trust, and consequently buy, more from sites found using a search engines rather than a banner advertisement . Therefore it is useless to create a very functional and beautiful website which has a poor rating like it does not make sense to open a new shop without registering it with a phone book, since to contact or find it will be difficult.
Unfortunately, although you will follow all the basic rules of the SEO, that does not automatically guarantee top ranking. The main reason of this situation is that there are lots of pages which try to get the highest ranks with over optimization, so that the search engines are very careful in the ranking process; they try to detect suspicious over optimized sites which use the so-called black hat SEO techniques like hidden text, cloaking, doorway pages, keywords stuffing and the like.